diff --git a/A00_Common/spreadsheet/spreadsheet_functions.ts b/A00_Common/spreadsheet/spreadsheet_functions.ts
index d0cabc22..a92ef894 100644
--- a/A00_Common/spreadsheet/spreadsheet_functions.ts
+++ b/A00_Common/spreadsheet/spreadsheet_functions.ts
@@ -1,18 +1,21 @@
 /* =============================================================================
  * spreadsheet_functions.ts  (주인 B)
- * 함수 표 — 이름(대문자) → 뜻. 몸은 `spreadsheet_functions_math.ts` · `_misc.ts` 에 두고 여기서 모음.
- * 1단계 약 45 — 수학 SUM PRODUCT SUMPRODUCT ROUND ROUNDUP ROUNDDOWN INT TRUNC CEILING FLOOR ABS MOD
- *   POWER SQRT PI SIN COS TAN ASIN ACOS ATAN RADIANS DEGREES MIN MAX AVERAGE · 논리 IF AND OR NOT IFERROR ·
- *   글 CONCATENATE FIXED TEXT LEN LEFT RIGHT MID VALUE · 찾기 VLOOKUP HLOOKUP INDEX MATCH CHOOSE ·
- *   세기 COUNT COUNTA COUNTIF SUMIF. 뜻 · 경계값은 엑셀과 같게(Formula.js 는 시험 대조 답으로만).
+ * 함수 표 — 이름(대문자) → 뜻. 몸은 `spreadsheet_functions_math.ts` · `_misc.ts` · `_lookup.ts` 에
+ * 두고 여기서 모음. 1단계 약 45 + 2단계 첫 묶음(2026-09-27) — 아래 `FUNC_HELP_BATCH2`(sub1 의
+ * `spreadsheet_func_help.ts` 가 읽어 이름 목록에 더할 것 — 그 파일은 sub1 몫이라 안 고침).
  * 없는 이름 = `#NAME?` · 인자 수가 min · max 밖이면 A 의 eval 이 `#VALUE!` + 까닭(엑셀은 입력을 막음).
  * ========================================================================== */
 
 import type { SheetFunction } from "./spreadsheet_types";
 import { MATH_FUNCTIONS } from "./spreadsheet_functions_math";
 import { MISC_FUNCTIONS } from "./spreadsheet_functions_misc";
+import { LOOKUP_FUNCTIONS } from "./spreadsheet_functions_lookup";
 
-const TABLE: Record<string, SheetFunction> = { ...MATH_FUNCTIONS, ...MISC_FUNCTIONS };
+const TABLE: Record<string, SheetFunction> = {
+  ...MATH_FUNCTIONS,
+  ...MISC_FUNCTIONS,
+  ...LOOKUP_FUNCTIONS,
+};
 
 export function getFunction(name: string): SheetFunction | undefined {
   return TABLE[name.toUpperCase()];
@@ -22,3 +25,97 @@ export function getFunction(name: string): SheetFunction | undefined {
 export function functionNames(): string[] {
   return Object.keys(TABLE).sort();
 }
+
+/** 2단계 첫 묶음(2026-09-27) — sub1 `spreadsheet_func_help.ts` 의 `TABLE` 에 이 모양대로 더할 것.
+ * `이름` · `꼴`(인자 모양 · 대괄호 = 생략 가능) · `뜻`(한 줄). */
+export interface FuncHelpEntry {
+  이름: string;
+  꼴: string;
+  뜻: string;
+}
+
+export const FUNC_HELP_BATCH2: FuncHelpEntry[] = [
+  { 이름: "MROUND", 꼴: "MROUND(수, 배수)", 뜻: "배수의 가장 가까운 정수 배로 반올림" },
+  { 이름: "ODD", 꼴: "ODD(수)", 뜻: "홀수로 올림(0 에서 먼 쪽)" },
+  { 이름: "EVEN", 꼴: "EVEN(수)", 뜻: "짝수로 올림(0 에서 먼 쪽)" },
+  { 이름: "LOG", 꼴: "LOG(수, [밑=10])", 뜻: "로그(밑 지정)" },
+  { 이름: "LOG10", 꼴: "LOG10(수)", 뜻: "상용로그" },
+  { 이름: "LN", 꼴: "LN(수)", 뜻: "자연로그" },
+  { 이름: "EXP", 꼴: "EXP(수)", 뜻: "e 의 거듭제곱" },
+  {
+    이름: "SUMIFS",
+    꼴: "SUMIFS(합할범위, 조건범위1, 조건1, [조건범위2, 조건2], …)",
+    뜻: "여러 조건에 다 맞는 칸의 합",
+  },
+  {
+    이름: "COUNTIFS",
+    꼴: "COUNTIFS(조건범위1, 조건1, [조건범위2, 조건2], …)",
+    뜻: "여러 조건에 다 맞는 칸 개수",
+  },
+  {
+    이름: "AVERAGEIF",
+    꼴: "AVERAGEIF(범위, 조건, [평균범위])",
+    뜻: "조건에 맞는 칸(또는 짝 칸)의 평균",
+  },
+  {
+    이름: "AVERAGEIFS",
+    꼴: "AVERAGEIFS(평균범위, 조건범위1, 조건1, …)",
+    뜻: "여러 조건에 다 맞는 칸의 평균",
+  },
+  {
+    이름: "MAXIFS",
+    꼴: "MAXIFS(최대범위, 조건범위1, 조건1, …)",
+    뜻: "여러 조건에 다 맞는 칸의 최댓값",
+  },
+  {
+    이름: "MINIFS",
+    꼴: "MINIFS(최소범위, 조건범위1, 조건1, …)",
+    뜻: "여러 조건에 다 맞는 칸의 최솟값",
+  },
+  {
+    이름: "IFS",
+    꼴: "IFS(조건1, 값1, [조건2, 값2], …)",
+    뜻: "처음으로 참인 조건의 값",
+  },
+  {
+    이름: "SWITCH",
+    꼴: "SWITCH(식, 값1, 결과1, [값2, 결과2], …, [기본값])",
+    뜻: "식과 같은 값을 찾아 그 결과",
+  },
+  {
+    이름: "XLOOKUP",
+    꼴: "XLOOKUP(찾을값, 찾을범위, 돌려줄범위, [못찾으면], [맞춤꼴], [찾는방향])",
+    뜻: "찾을범위에서 찾아 돌려줄범위의 같은 자리 값",
+  },
+  {
+    이름: "TEXTJOIN",
+    꼴: "TEXTJOIN(구분자, 빈칸건너뜀, 글1, [글2], …)",
+    뜻: "구분자로 여러 글을 이어 붙임",
+  },
+  { 이름: "TRIM", 꼴: "TRIM(글)", 뜻: "앞뒤 · 겹친 빈칸을 뺌" },
+  { 이름: "UPPER", 꼴: "UPPER(글)", 뜻: "대문자로" },
+  { 이름: "LOWER", 꼴: "LOWER(글)", 뜻: "소문자로" },
+  {
+    이름: "SUBSTITUTE",
+    꼴: "SUBSTITUTE(글, 옛글, 새글, [몇번째])",
+    뜻: "글 안 옛글을 새글로 바꿈",
+  },
+  { 이름: "REPLACE", 꼴: "REPLACE(글, 시작, 글자수, 새글)", 뜻: "자리로 콕 집어 바꿈" },
+  { 이름: "FIND", 꼴: "FIND(찾을글, 안글, [시작])", 뜻: "글자 그대로 찾음(대소문자 가림)" },
+  {
+    이름: "SEARCH",
+    꼴: "SEARCH(찾을글, 안글, [시작])",
+    뜻: "찾음(대소문자 안 가림 · * ? 자리표시)",
+  },
+  { 이름: "REPT", 꼴: "REPT(글, 번)", 뜻: "글을 번 만큼 되풀이" },
+  { 이름: "ISNUMBER", 꼴: "ISNUMBER(값)", 뜻: "수면 참" },
+  { 이름: "ISTEXT", 꼴: "ISTEXT(값)", 뜻: "글이면 참" },
+  { 이름: "ISBLANK", 꼴: "ISBLANK(값)", 뜻: "빈 칸이면 참" },
+  { 이름: "ISERROR", 꼴: "ISERROR(값)", 뜻: "오류 값이면 참" },
+  { 이름: "NA", 꼴: "NA()", 뜻: "#N/A 오류를 만듦" },
+  { 이름: "TODAY", 꼴: "TODAY()", 뜻: "오늘 날짜(일련번호)" },
+  { 이름: "DATE", 꼴: "DATE(년, 월, 일)", 뜻: "날짜 일련번호를 만듦" },
+  { 이름: "YEAR", 꼴: "YEAR(일련번호)", 뜻: "연도" },
+  { 이름: "MONTH", 꼴: "MONTH(일련번호)", 뜻: "월" },
+  { 이름: "DAY", 꼴: "DAY(일련번호)", 뜻: "일" },
+];
diff --git a/A00_Common/spreadsheet/spreadsheet_functions_lookup.ts b/A00_Common/spreadsheet/spreadsheet_functions_lookup.ts
new file mode 100644
index 00000000..214caa5f
--- /dev/null
+++ b/A00_Common/spreadsheet/spreadsheet_functions_lookup.ts
@@ -0,0 +1,536 @@
+/* =============================================================================
+ * spreadsheet_functions_lookup.ts  (주인 B · misc 700 줄 넘어 2026-09-27 쪼갬)
+ * 찾기 · 조건부 세기·합·평균·최대·최소 함수. `spreadsheet_functions_misc.ts` 에서
+ * VLOOKUP · HLOOKUP · INDEX · MATCH · CHOOSE · COUNT · COUNTA · COUNTIF · SUMIF ·
+ * SUMIFS · COUNTIFS · AVERAGEIF(S) · MAXIFS · MINIFS · IFS · SWITCH · XLOOKUP 를 옮겨 옴.
+ * 형 바꾸기 도우미는 `spreadsheet_functions_math.ts` 공용 것을 씀.
+ * ========================================================================== */
+
+import {
+  ZERO,
+  add,
+  cmp,
+  div,
+  frac,
+  parseDecimal,
+  type Frac,
+} from "@ui/sheet/ui_template_sheet_frac";
+import type { ErrorValue, LazyArg, RangeValue, Scalar, SheetFunction } from "./spreadsheet_types";
+import {
+  bool,
+  collectNumbers,
+  fracToDouble,
+  isErr,
+  isFrac,
+  isRange,
+  mkErr,
+  num,
+  toNumber,
+  toScalar,
+} from "./spreadsheet_functions_math";
+
+const ONE = frac(1n);
+
+// ── 값 견줌(찾기 · 세기 함수 공용) ───────────────────────────────────────────
+
+function typeRank(v: Scalar): number {
+  if (v === null) return -1;
+  if (isFrac(v)) return 0;
+  if (typeof v === "string") return 1;
+  if (typeof v === "boolean") return 2;
+  return 3;
+}
+
+function compareScalars(a: Scalar, b: Scalar): number {
+  if (isFrac(a) && isFrac(b)) return cmp(a, b);
+  if (typeof a === "string" && typeof b === "string") {
+    const la = a.toUpperCase();
+    const lb = b.toUpperCase();
+    return la < lb ? -1 : la > lb ? 1 : 0;
+  }
+  if (typeof a === "boolean" && typeof b === "boolean") return a === b ? 0 : a ? 1 : -1;
+  return 0;
+}
+
+function equalScalars(a: Scalar, b: Scalar): boolean {
+  return typeRank(a) === typeRank(b) && compareScalars(a, b) === 0;
+}
+
+function wrapScalar(v: Scalar): RangeValue {
+  return { kind: "range", rows: 1, cols: 1, at: () => v };
+}
+
+// ── 조건 글(`>10` · `<=5` · `사과*`) ─────────────────────────────────────────
+
+function wildcardToRegex(text: string): RegExp {
+  const escaped = text
+    .replace(/[.+^${}()|[\]\\]/g, "\\$&")
+    .replace(/\*/g, ".*")
+    .replace(/\?/g, ".");
+  return new RegExp(`^${escaped}$`, "i");
+}
+
+function parseCriteria(crit: Scalar): (cell: Scalar) => boolean {
+  if (crit === null) return (cell) => cell === null;
+  if (typeof crit === "boolean") return (cell) => typeof cell === "boolean" && cell === crit;
+  if (isFrac(crit)) return (cell) => isFrac(cell) && cmp(cell, crit) === 0;
+  if (isErr(crit)) return () => false;
+  const m = /^(<=|>=|<>|<|>|=)?(.*)$/.exec(crit);
+  const op = m?.[1] ?? "";
+  const rest = m?.[2] ?? crit;
+  let numRest: Frac | null = null;
+  try {
+    numRest = rest.trim() === "" ? null : parseDecimal(rest);
+  } catch {
+    numRest = null;
+  }
+  if (numRest !== null) {
+    const nr = numRest;
+    return (cell) => {
+      if (!isFrac(cell)) return false;
+      const c = cmp(cell, nr);
+      if (op === "<=") return c <= 0;
+      if (op === ">=") return c >= 0;
+      if (op === "<>") return c !== 0;
+      if (op === "<") return c < 0;
+      if (op === ">") return c > 0;
+      return c === 0;
+    };
+  }
+  const pat = wildcardToRegex(rest);
+  if (op === "<>") return (cell) => !(typeof cell === "string" && pat.test(cell));
+  return (cell) => typeof cell === "string" && pat.test(cell);
+}
+
+/** `args[from]` 부터 (범위,조건) 짝을 이어가며 모두 맞는 자리만 참 — *IFS 함수 공용.
+ * `shape` 범위와 크기가 다른 조건 범위가 있으면 `#VALUE!`. */
+function criteriaMask(args: LazyArg[], from: number, shape: RangeValue): boolean[] | ErrorValue {
+  const mask = new Array<boolean>(shape.rows * shape.cols).fill(true);
+  for (let i = from; i + 1 < args.length; i += 2) {
+    const rangeArg = args[i]();
+    if (!isRange(rangeArg)) return mkErr("#VALUE!");
+    if (rangeArg.rows !== shape.rows || rangeArg.cols !== shape.cols) {
+      return mkErr("#VALUE!", "조건 범위 크기가 다름");
+    }
+    const crit = toScalar(args[i + 1]());
+    if (isErr(crit)) return crit;
+    const pred = parseCriteria(crit);
+    let k = 0;
+    for (let r = 0; r < shape.rows; r++) {
+      for (let c = 0; c < shape.cols; c++) {
+        if (mask[k] && !pred(rangeArg.at(r, c))) mask[k] = false;
+        k++;
+      }
+    }
+  }
+  return mask;
+}
+
+// ── 함수 표 ──────────────────────────────────────────────────────────────
+
+export const LOOKUP_FUNCTIONS: Record<string, SheetFunction> = {
+  VLOOKUP: {
+    min: 3,
+    max: 4,
+    call: (args) => {
+      const lookup = toScalar(args[0]());
+      if (isErr(lookup)) return lookup;
+      const table = args[1]();
+      if (!isRange(table)) return mkErr("#VALUE!");
+      const colN = num(args[2]());
+      if (isErr(colN)) return colN;
+      const col = Math.trunc(fracToDouble(colN)) - 1;
+      if (col < 0 || col >= table.cols) return mkErr("#REF!");
+      const approxRaw = args.length > 3 ? bool(args[3]()) : true;
+      if (isErr(approxRaw)) return approxRaw;
+      if (approxRaw) {
+        let best = -1;
+        for (let r = 0; r < table.rows; r++) {
+          const key = table.at(r, 0);
+          if (typeRank(key) !== typeRank(lookup)) {
+            if (best >= 0) break;
+            continue;
+          }
+          if (compareScalars(key, lookup) <= 0) best = r;
+          else break;
+        }
+        if (best < 0) return mkErr("#N/A");
+        return table.at(best, col);
+      }
+      for (let r = 0; r < table.rows; r++) {
+        if (equalScalars(table.at(r, 0), lookup)) return table.at(r, col);
+      }
+      return mkErr("#N/A");
+    },
+  },
+  HLOOKUP: {
+    min: 3,
+    max: 4,
+    call: (args) => {
+      const lookup = toScalar(args[0]());
+      if (isErr(lookup)) return lookup;
+      const table = args[1]();
+      if (!isRange(table)) return mkErr("#VALUE!");
+      const rowN = num(args[2]());
+      if (isErr(rowN)) return rowN;
+      const row = Math.trunc(fracToDouble(rowN)) - 1;
+      if (row < 0 || row >= table.rows) return mkErr("#REF!");
+      const approxRaw = args.length > 3 ? bool(args[3]()) : true;
+      if (isErr(approxRaw)) return approxRaw;
+      if (approxRaw) {
+        let best = -1;
+        for (let c = 0; c < table.cols; c++) {
+          const key = table.at(0, c);
+          if (typeRank(key) !== typeRank(lookup)) {
+            if (best >= 0) break;
+            continue;
+          }
+          if (compareScalars(key, lookup) <= 0) best = c;
+          else break;
+        }
+        if (best < 0) return mkErr("#N/A");
+        return table.at(row, best);
+      }
+      for (let c = 0; c < table.cols; c++) {
+        if (equalScalars(table.at(0, c), lookup)) return table.at(row, c);
+      }
+      return mkErr("#N/A");
+    },
+  },
+  INDEX: {
+    min: 2,
+    max: 3,
+    call: (args) => {
+      const rangeArg = args[0]();
+      if (isErr(rangeArg)) return rangeArg;
+      const range = isRange(rangeArg) ? rangeArg : wrapScalar(rangeArg);
+      const rowN = num(args[1]());
+      if (isErr(rowN)) return rowN;
+      const row = Math.trunc(fracToDouble(rowN));
+      const colN = args.length > 2 ? num(args[2]()) : frac(range.cols === 1 ? 1n : 0n);
+      if (isErr(colN)) return colN;
+      const col = Math.trunc(fracToDouble(colN));
+      if (row === 0 && col === 0) return mkErr("#VALUE!");
+      if (row === 0) {
+        if (col < 1 || col > range.cols) return mkErr("#REF!");
+        const c = col - 1;
+        return { kind: "range", rows: range.rows, cols: 1, at: (r: number) => range.at(r, c) };
+      }
+      if (col === 0) {
+        if (row < 1 || row > range.rows) return mkErr("#REF!");
+        const r = row - 1;
+        return {
+          kind: "range",
+          rows: 1,
+          cols: range.cols,
+          at: (_r: number, c: number) => range.at(r, c),
+        };
+      }
+      if (row < 1 || row > range.rows || col < 1 || col > range.cols) return mkErr("#REF!");
+      return range.at(row - 1, col - 1);
+    },
+  },
+  MATCH: {
+    min: 2,
+    max: 3,
+    call: (args) => {
+      const lookup = toScalar(args[0]());
+      if (isErr(lookup)) return lookup;
+      const rangeArg = args[1]();
+      if (!isRange(rangeArg)) return mkErr("#VALUE!");
+      if (rangeArg.rows !== 1 && rangeArg.cols !== 1) {
+        return mkErr("#VALUE!", "한 줄 · 한 칸짜리 범위만");
+      }
+      const n = rangeArg.rows === 1 ? rangeArg.cols : rangeArg.rows;
+      const at = (i: number): Scalar =>
+        rangeArg.rows === 1 ? rangeArg.at(0, i) : rangeArg.at(i, 0);
+      const modeN = args.length > 2 ? num(args[2]()) : ONE;
+      if (isErr(modeN)) return modeN;
+      const mode = Math.trunc(fracToDouble(modeN));
+      if (mode === 0) {
+        for (let i = 0; i < n; i++) if (equalScalars(at(i), lookup)) return frac(BigInt(i + 1));
+        return mkErr("#N/A");
+      }
+      let best = -1;
+      for (let i = 0; i < n; i++) {
+        const key = at(i);
+        if (typeRank(key) !== typeRank(lookup)) {
+          if (best >= 0) break;
+          continue;
+        }
+        const c = compareScalars(key, lookup);
+        if (mode > 0 ? c <= 0 : c >= 0) best = i;
+        else break;
+      }
+      if (best < 0) return mkErr("#N/A");
+      return frac(BigInt(best + 1));
+    },
+  },
+  CHOOSE: {
+    min: 2,
+    call: (args) => {
+      const idxN = num(args[0]());
+      if (isErr(idxN)) return idxN;
+      const idx = Math.trunc(fracToDouble(idxN));
+      if (idx < 1 || idx > args.length - 1) return mkErr("#VALUE!");
+      return args[idx]();
+    },
+  },
+  COUNT: {
+    min: 0,
+    call: (args) => {
+      const values = collectNumbers(args, false, false);
+      return isErr(values) ? values : frac(BigInt(values.length));
+    },
+  },
+  COUNTA: {
+    min: 0,
+    call: (args) => {
+      let count = 0;
+      for (const a of args) {
+        const v = a();
+        if (isRange(v)) {
+          for (let r = 0; r < v.rows; r++) {
+            for (let c = 0; c < v.cols; c++) if (v.at(r, c) !== null) count++;
+          }
+        } else if (v !== null) {
+          count++;
+        }
+      }
+      return frac(BigInt(count));
+    },
+  },
+  COUNTIF: {
+    min: 2,
+    max: 2,
+    call: (args) => {
+      const range = args[0]();
+      if (!isRange(range)) return mkErr("#VALUE!");
+      const crit = toScalar(args[1]());
+      if (isErr(crit)) return crit;
+      const pred = parseCriteria(crit);
+      let count = 0;
+      for (let r = 0; r < range.rows; r++) {
+        for (let c = 0; c < range.cols; c++) if (pred(range.at(r, c))) count++;
+      }
+      return frac(BigInt(count));
+    },
+  },
+  SUMIF: {
+    min: 2,
+    max: 3,
+    call: (args) => {
+      const range = args[0]();
+      if (!isRange(range)) return mkErr("#VALUE!");
+      const crit = toScalar(args[1]());
+      if (isErr(crit)) return crit;
+      const pred = parseCriteria(crit);
+      const sumRange = args.length > 2 ? args[2]() : range;
+      if (!isRange(sumRange)) return mkErr("#VALUE!");
+      if (sumRange.rows !== range.rows || sumRange.cols !== range.cols) {
+        return mkErr("#VALUE!", "합 범위 크기가 다름");
+      }
+      let total = ZERO;
+      for (let r = 0; r < range.rows; r++) {
+        for (let c = 0; c < range.cols; c++) {
+          if (!pred(range.at(r, c))) continue;
+          const n = toNumber(sumRange.at(r, c));
+          if (isErr(n)) return n;
+          total = add(total, n);
+        }
+      }
+      return total;
+    },
+  },
+  SUMIFS: {
+    min: 3,
+    call: (args) => {
+      const sumRange = args[0]();
+      if (!isRange(sumRange)) return mkErr("#VALUE!");
+      const mask = criteriaMask(args, 1, sumRange);
+      if (isErr(mask)) return mask;
+      let total = ZERO;
+      let k = 0;
+      for (let r = 0; r < sumRange.rows; r++) {
+        for (let c = 0; c < sumRange.cols; c++) {
+          if (mask[k]) {
+            const n = toNumber(sumRange.at(r, c));
+            if (isErr(n)) return n;
+            total = add(total, n);
+          }
+          k++;
+        }
+      }
+      return total;
+    },
+  },
+  COUNTIFS: {
+    min: 2,
+    call: (args) => {
+      const first = args[0]();
+      if (!isRange(first)) return mkErr("#VALUE!");
+      const mask = criteriaMask(args, 0, first);
+      if (isErr(mask)) return mask;
+      return frac(BigInt(mask.filter(Boolean).length));
+    },
+  },
+  AVERAGEIF: {
+    min: 2,
+    max: 3,
+    call: (args) => {
+      const range = args[0]();
+      if (!isRange(range)) return mkErr("#VALUE!");
+      const crit = toScalar(args[1]());
+      if (isErr(crit)) return crit;
+      const pred = parseCriteria(crit);
+      const avgRange = args.length > 2 ? args[2]() : range;
+      if (!isRange(avgRange)) return mkErr("#VALUE!");
+      if (avgRange.rows !== range.rows || avgRange.cols !== range.cols) {
+        return mkErr("#VALUE!", "평균 범위 크기가 다름");
+      }
+      let total = ZERO;
+      let count = 0;
+      for (let r = 0; r < range.rows; r++) {
+        for (let c = 0; c < range.cols; c++) {
+          if (!pred(range.at(r, c))) continue;
+          const n = toNumber(avgRange.at(r, c));
+          if (isErr(n)) return n;
+          total = add(total, n);
+          count++;
+        }
+      }
+      return count === 0 ? mkErr("#DIV/0!") : div(total, frac(BigInt(count)));
+    },
+  },
+  AVERAGEIFS: {
+    min: 3,
+    call: (args) => {
+      const avgRange = args[0]();
+      if (!isRange(avgRange)) return mkErr("#VALUE!");
+      const mask = criteriaMask(args, 1, avgRange);
+      if (isErr(mask)) return mask;
+      let total = ZERO;
+      let count = 0;
+      let k = 0;
+      for (let r = 0; r < avgRange.rows; r++) {
+        for (let c = 0; c < avgRange.cols; c++) {
+          if (mask[k]) {
+            const n = toNumber(avgRange.at(r, c));
+            if (isErr(n)) return n;
+            total = add(total, n);
+            count++;
+          }
+          k++;
+        }
+      }
+      return count === 0 ? mkErr("#DIV/0!") : div(total, frac(BigInt(count)));
+    },
+  },
+  MAXIFS: {
+    min: 3,
+    call: (args) => {
+      const targetRange = args[0]();
+      if (!isRange(targetRange)) return mkErr("#VALUE!");
+      const mask = criteriaMask(args, 1, targetRange);
+      if (isErr(mask)) return mask;
+      let best: Frac | null = null;
+      let k = 0;
+      for (let r = 0; r < targetRange.rows; r++) {
+        for (let c = 0; c < targetRange.cols; c++) {
+          if (mask[k]) {
+            const cell = targetRange.at(r, c);
+            if (isFrac(cell) && (best === null || cmp(cell, best) > 0)) best = cell;
+          }
+          k++;
+        }
+      }
+      return best ?? ZERO;
+    },
+  },
+  MINIFS: {
+    min: 3,
+    call: (args) => {
+      const targetRange = args[0]();
+      if (!isRange(targetRange)) return mkErr("#VALUE!");
+      const mask = criteriaMask(args, 1, targetRange);
+      if (isErr(mask)) return mask;
+      let best: Frac | null = null;
+      let k = 0;
+      for (let r = 0; r < targetRange.rows; r++) {
+        for (let c = 0; c < targetRange.cols; c++) {
+          if (mask[k]) {
+            const cell = targetRange.at(r, c);
+            if (isFrac(cell) && (best === null || cmp(cell, best) < 0)) best = cell;
+          }
+          k++;
+        }
+      }
+      return best ?? ZERO;
+    },
+  },
+  IFS: {
+    min: 2,
+    call: (args) => {
+      for (let i = 0; i + 1 < args.length; i += 2) {
+        const c = bool(args[i]());
+        if (isErr(c)) return c;
+        if (c) return args[i + 1]();
+      }
+      return mkErr("#N/A");
+    },
+  },
+  SWITCH: {
+    min: 3,
+    call: (args) => {
+      const target = toScalar(args[0]());
+      if (isErr(target)) return target;
+      let i = 1;
+      for (; i + 1 < args.length; i += 2) {
+        const cand = toScalar(args[i]());
+        if (isErr(cand)) return cand;
+        if (equalScalars(target, cand)) return args[i + 1]();
+      }
+      return i < args.length ? args[i]() : mkErr("#N/A");
+    },
+  },
+  XLOOKUP: {
+    min: 3,
+    max: 6,
+    call: (args) => {
+      const lookup = toScalar(args[0]());
+      if (isErr(lookup)) return lookup;
+      const lookupRange = args[1]();
+      const returnRange = args[2]();
+      if (!isRange(lookupRange) || !isRange(returnRange)) return mkErr("#VALUE!");
+      const n = lookupRange.rows * lookupRange.cols;
+      if (n !== returnRange.rows * returnRange.cols) {
+        return mkErr("#VALUE!", "찾을 범위 · 돌려줄 범위 크기가 다름");
+      }
+      const at = (rv: RangeValue, i: number): Scalar => (rv.rows === 1 ? rv.at(0, i) : rv.at(i, 0));
+      const modeN = args.length > 4 ? num(args[4]()) : ZERO;
+      if (isErr(modeN)) return modeN;
+      const mode = Math.trunc(fracToDouble(modeN));
+      const searchN = args.length > 5 ? num(args[5]()) : ONE;
+      if (isErr(searchN)) return searchN;
+      const reverse = Math.trunc(fracToDouble(searchN)) < 0;
+      let best = -1;
+      for (let step = 0; step < n; step++) {
+        const i = reverse ? n - 1 - step : step;
+        const key = at(lookupRange, i);
+        if (typeRank(key) !== typeRank(lookup)) continue;
+        const c = compareScalars(key, lookup);
+        if (c === 0) {
+          best = i;
+          break;
+        }
+        if (mode === 1 && c > 0) {
+          if (best < 0 || compareScalars(key, at(lookupRange, best)) < 0) best = i;
+        } else if (mode === -1 && c < 0) {
+          if (best < 0 || compareScalars(key, at(lookupRange, best)) > 0) best = i;
+        }
+      }
+      if (best < 0) return args.length > 3 ? args[3]() : mkErr("#N/A");
+      return at(returnRange, best);
+    },
+  },
+};
diff --git a/A00_Common/spreadsheet/spreadsheet_functions_math.ts b/A00_Common/spreadsheet/spreadsheet_functions_math.ts
index 99f21e12..6d65b53e 100644
--- a/A00_Common/spreadsheet/spreadsheet_functions_math.ts
+++ b/A00_Common/spreadsheet/spreadsheet_functions_math.ts
@@ -415,4 +415,76 @@ export const MATH_FUNCTIONS: Record<string, SheetFunction> = {
       return div(values.reduce(add, ZERO), frac(BigInt(values.length)));
     },
   },
+  MROUND: {
+    min: 2,
+    max: 2,
+    call: (args) => {
+      const n = num(args[0]());
+      if (isErr(n)) return n;
+      const m = num(args[1]());
+      if (isErr(m)) return m;
+      if (cmp(m, ZERO) === 0) return ZERO;
+      if (cmp(n, ZERO) !== 0 && cmp(n, ZERO) > 0 !== cmp(m, ZERO) > 0) {
+        return mkErr("#NUM!", "수 · 배수의 부호가 다름");
+      }
+      return mul(frac(toInteger(div(n, m), "round")), m);
+    },
+  },
+  ODD: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const n = num(args[0]());
+      if (isErr(n)) return n;
+      let v = toInteger(n, "away");
+      if (v === 0n) v = 1n;
+      else if (v % 2n === 0n) v += v < 0n ? -1n : 1n;
+      return frac(v);
+    },
+  },
+  EVEN: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const n = num(args[0]());
+      if (isErr(n)) return n;
+      let v = toInteger(n, "away");
+      if (v % 2n !== 0n) v += v < 0n ? -1n : 1n;
+      return frac(v);
+    },
+  },
+  LOG: {
+    min: 1,
+    max: 2,
+    call: (args) => {
+      const n = num(args[0]());
+      if (isErr(n)) return n;
+      if (cmp(n, ZERO) <= 0) return mkErr("#NUM!");
+      const base = args.length > 1 ? num(args[1]()) : frac(10n);
+      if (isErr(base)) return base;
+      if (cmp(base, ZERO) <= 0 || cmp(base, ONE) === 0) return mkErr("#NUM!");
+      return fromDouble(Math.log(fracToDouble(n)) / Math.log(fracToDouble(base)));
+    },
+  },
+  LOG10: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const n = num(args[0]());
+      if (isErr(n)) return n;
+      if (cmp(n, ZERO) <= 0) return mkErr("#NUM!");
+      return fromDouble(Math.log10(fracToDouble(n)));
+    },
+  },
+  LN: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const n = num(args[0]());
+      if (isErr(n)) return n;
+      if (cmp(n, ZERO) <= 0) return mkErr("#NUM!");
+      return fromDouble(Math.log(fracToDouble(n)));
+    },
+  },
+  EXP: unaryDouble(Math.exp),
 };
diff --git a/A00_Common/spreadsheet/spreadsheet_functions_misc.ts b/A00_Common/spreadsheet/spreadsheet_functions_misc.ts
index 10d4916a..dd33073f 100644
--- a/A00_Common/spreadsheet/spreadsheet_functions_misc.ts
+++ b/A00_Common/spreadsheet/spreadsheet_functions_misc.ts
@@ -1,12 +1,12 @@
 /* =============================================================================
  * spreadsheet_functions_misc.ts  (주인 B)
- * 논리 · 글 · 찾기 · 세기 함수. 형 바꾸기 도우미는 `spreadsheet_functions_math.ts` 공용 것을 씀.
- * 뜻 · 경계값은 엑셀과 같게(Formula.js 는 시험 대조 답으로만).
+ * 논리 · 글 · 정보 · 날짜 함수. 찾기 · 조건부 세기/합/평균/최대/최소는
+ * `spreadsheet_functions_lookup.ts` 로 옮김(700 줄 규칙 · 2026-09-27).
+ * 형 바꾸기 도우미는 `spreadsheet_functions_math.ts` 공용 것을 씀.
  * ========================================================================== */
 
 import {
   ZERO,
-  add,
   cmp,
   frac,
   mul,
@@ -15,12 +15,12 @@ import {
   toInteger,
   type Frac,
 } from "@ui/sheet/ui_template_sheet_frac";
-import type { ErrorValue, LazyArg, RangeValue, Scalar, SheetFunction } from "./spreadsheet_types";
+import type { ErrorValue, LazyArg, SheetFunction } from "./spreadsheet_types";
 import { formatValue } from "./spreadsheet_numfmt";
 import {
   bool,
-  collectNumbers,
   fracToDouble,
+  fromDouble,
   isErr,
   isFrac,
   isRange,
@@ -28,82 +28,19 @@ import {
   num,
   str,
   toBool,
-  toNumber,
   toScalar,
   toText,
 } from "./spreadsheet_functions_math";
 
 const ONE = frac(1n);
 
-// ── 값 견줌(찾기 · 세기 함수 공용) ───────────────────────────────────────────
-
-function typeRank(v: Scalar): number {
-  if (v === null) return -1;
-  if (isFrac(v)) return 0;
-  if (typeof v === "string") return 1;
-  if (typeof v === "boolean") return 2;
-  return 3;
-}
-
-function compareScalars(a: Scalar, b: Scalar): number {
-  if (isFrac(a) && isFrac(b)) return cmp(a, b);
-  if (typeof a === "string" && typeof b === "string") {
-    const la = a.toUpperCase();
-    const lb = b.toUpperCase();
-    return la < lb ? -1 : la > lb ? 1 : 0;
-  }
-  if (typeof a === "boolean" && typeof b === "boolean") return a === b ? 0 : a ? 1 : -1;
-  return 0;
-}
-
-function equalScalars(a: Scalar, b: Scalar): boolean {
-  return typeRank(a) === typeRank(b) && compareScalars(a, b) === 0;
-}
-
-function wrapScalar(v: Scalar): RangeValue {
-  return { kind: "range", rows: 1, cols: 1, at: () => v };
-}
-
-// ── 조건 글(`>10` · `<=5` · `사과*`) ─────────────────────────────────────────
-
-function wildcardToRegex(text: string): RegExp {
+/** SEARCH — 통짜 맞춤이 아니라 안 어디서든 찾음(자리 없이 그대로 씀). */
+function wildcardToSearchRegex(text: string): RegExp {
   const escaped = text
     .replace(/[.+^${}()|[\]\\]/g, "\\$&")
     .replace(/\*/g, ".*")
     .replace(/\?/g, ".");
-  return new RegExp(`^${escaped}$`, "i");
-}
-
-function parseCriteria(crit: Scalar): (cell: Scalar) => boolean {
-  if (crit === null) return (cell) => cell === null;
-  if (typeof crit === "boolean") return (cell) => typeof cell === "boolean" && cell === crit;
-  if (isFrac(crit)) return (cell) => isFrac(cell) && cmp(cell, crit) === 0;
-  if (isErr(crit)) return () => false;
-  const m = /^(<=|>=|<>|<|>|=)?(.*)$/.exec(crit);
-  const op = m?.[1] ?? "";
-  const rest = m?.[2] ?? crit;
-  let numRest: Frac | null = null;
-  try {
-    numRest = rest.trim() === "" ? null : parseDecimal(rest);
-  } catch {
-    numRest = null;
-  }
-  if (numRest !== null) {
-    const nr = numRest;
-    return (cell) => {
-      if (!isFrac(cell)) return false;
-      const c = cmp(cell, nr);
-      if (op === "<=") return c <= 0;
-      if (op === ">=") return c >= 0;
-      if (op === "<>") return c !== 0;
-      if (op === "<") return c < 0;
-      if (op === ">") return c > 0;
-      return c === 0;
-    };
-  }
-  const pat = wildcardToRegex(rest);
-  if (op === "<>") return (cell) => !(typeof cell === "string" && pat.test(cell));
-  return (cell) => typeof cell === "string" && pat.test(cell);
+  return new RegExp(escaped, "i");
 }
 
 // ── 숫자 → 고정 소수 글(FIXED) ───────────────────────────────────────────────
@@ -126,8 +63,6 @@ function formatFixed(n: Frac, decimals: number, commas: boolean): string {
   return negative ? `-${body}` : body;
 }
 
-// ── 함수 표 ──────────────────────────────────────────────────────────────
-
 function collectBools(args: LazyArg[]): boolean[] | ErrorValue {
   const out: boolean[] = [];
   for (const a of args) {
@@ -152,6 +87,23 @@ function collectBools(args: LazyArg[]): boolean[] | ErrorValue {
   return out;
 }
 
+// ── 날짜 일련번호(엑셀 1900 체계 · 1970-01-01 = 25569) ───────────────────────
+// 1900 을 윤년 취급하는 옛 버그는 그대로 두지 않음(1900 년대 자체를 실무가 안 씀) —
+// 유닉스 자정 기준으로 바로 셈해 1900 년 2 월 안쪽만 어긋남(1단계 밖).
+
+const MS_PER_DAY = 86400000;
+const UNIX_EPOCH_AS_EXCEL_SERIAL = 25569;
+
+function serialToDate(serial: number): Date {
+  return new Date(Math.round((serial - UNIX_EPOCH_AS_EXCEL_SERIAL) * MS_PER_DAY));
+}
+
+function dateToSerial(d: Date): number {
+  return d.getTime() / MS_PER_DAY + UNIX_EPOCH_AS_EXCEL_SERIAL;
+}
+
+// ── 함수 표 ──────────────────────────────────────────────────────────────
+
 export const MISC_FUNCTIONS: Record<string, SheetFunction> = {
   IF: {
     min: 2,
@@ -311,217 +263,207 @@ export const MISC_FUNCTIONS: Record<string, SheetFunction> = {
       }
     },
   },
-  VLOOKUP: {
+  TEXTJOIN: {
     min: 3,
-    max: 4,
     call: (args) => {
-      const lookup = toScalar(args[0]());
-      if (isErr(lookup)) return lookup;
-      const table = args[1]();
-      if (!isRange(table)) return mkErr("#VALUE!");
-      const colN = num(args[2]());
-      if (isErr(colN)) return colN;
-      const col = Math.trunc(fracToDouble(colN)) - 1;
-      if (col < 0 || col >= table.cols) return mkErr("#REF!");
-      const approxRaw = args.length > 3 ? bool(args[3]()) : true;
-      if (isErr(approxRaw)) return approxRaw;
-      if (approxRaw) {
-        let best = -1;
-        for (let r = 0; r < table.rows; r++) {
-          const key = table.at(r, 0);
-          if (typeRank(key) !== typeRank(lookup)) {
-            if (best >= 0) break;
-            continue;
-          }
-          if (compareScalars(key, lookup) <= 0) best = r;
-          else break;
-        }
-        if (best < 0) return mkErr("#N/A");
-        return table.at(best, col);
-      }
-      for (let r = 0; r < table.rows; r++) {
-        if (equalScalars(table.at(r, 0), lookup)) return table.at(r, col);
-      }
-      return mkErr("#N/A");
-    },
-  },
-  HLOOKUP: {
-    min: 3,
-    max: 4,
-    call: (args) => {
-      const lookup = toScalar(args[0]());
-      if (isErr(lookup)) return lookup;
-      const table = args[1]();
-      if (!isRange(table)) return mkErr("#VALUE!");
-      const rowN = num(args[2]());
-      if (isErr(rowN)) return rowN;
-      const row = Math.trunc(fracToDouble(rowN)) - 1;
-      if (row < 0 || row >= table.rows) return mkErr("#REF!");
-      const approxRaw = args.length > 3 ? bool(args[3]()) : true;
-      if (isErr(approxRaw)) return approxRaw;
-      if (approxRaw) {
-        let best = -1;
-        for (let c = 0; c < table.cols; c++) {
-          const key = table.at(0, c);
-          if (typeRank(key) !== typeRank(lookup)) {
-            if (best >= 0) break;
-            continue;
-          }
-          if (compareScalars(key, lookup) <= 0) best = c;
-          else break;
-        }
-        if (best < 0) return mkErr("#N/A");
-        return table.at(row, best);
-      }
-      for (let c = 0; c < table.cols; c++) {
-        if (equalScalars(table.at(0, c), lookup)) return table.at(row, c);
-      }
-      return mkErr("#N/A");
-    },
-  },
-  INDEX: {
-    min: 2,
-    max: 3,
-    call: (args) => {
-      const rangeArg = args[0]();
-      if (isErr(rangeArg)) return rangeArg;
-      const range = isRange(rangeArg) ? rangeArg : wrapScalar(rangeArg);
-      const rowN = num(args[1]());
-      if (isErr(rowN)) return rowN;
-      const row = Math.trunc(fracToDouble(rowN));
-      const colN = args.length > 2 ? num(args[2]()) : frac(range.cols === 1 ? 1n : 0n);
-      if (isErr(colN)) return colN;
-      const col = Math.trunc(fracToDouble(colN));
-      if (row === 0 && col === 0) return mkErr("#VALUE!");
-      if (row === 0) {
-        if (col < 1 || col > range.cols) return mkErr("#REF!");
-        const c = col - 1;
-        return { kind: "range", rows: range.rows, cols: 1, at: (r: number) => range.at(r, c) };
-      }
-      if (col === 0) {
-        if (row < 1 || row > range.rows) return mkErr("#REF!");
-        const r = row - 1;
-        return {
-          kind: "range",
-          rows: 1,
-          cols: range.cols,
-          at: (_r: number, c: number) => range.at(r, c),
-        };
-      }
-      if (row < 1 || row > range.rows || col < 1 || col > range.cols) return mkErr("#REF!");
-      return range.at(row - 1, col - 1);
-    },
-  },
-  MATCH: {
-    min: 2,
-    max: 3,
-    call: (args) => {
-      const lookup = toScalar(args[0]());
-      if (isErr(lookup)) return lookup;
-      const rangeArg = args[1]();
-      if (!isRange(rangeArg)) return mkErr("#VALUE!");
-      if (rangeArg.rows !== 1 && rangeArg.cols !== 1) {
-        return mkErr("#VALUE!", "한 줄 · 한 칸짜리 범위만");
-      }
-      const n = rangeArg.rows === 1 ? rangeArg.cols : rangeArg.rows;
-      const at = (i: number): Scalar =>
-        rangeArg.rows === 1 ? rangeArg.at(0, i) : rangeArg.at(i, 0);
-      const modeN = args.length > 2 ? num(args[2]()) : ONE;
-      if (isErr(modeN)) return modeN;
-      const mode = Math.trunc(fracToDouble(modeN));
-      if (mode === 0) {
-        for (let i = 0; i < n; i++) if (equalScalars(at(i), lookup)) return frac(BigInt(i + 1));
-        return mkErr("#N/A");
-      }
-      let best = -1;
-      for (let i = 0; i < n; i++) {
-        const key = at(i);
-        if (typeRank(key) !== typeRank(lookup)) {
-          if (best >= 0) break;
-          continue;
-        }
-        const c = compareScalars(key, lookup);
-        if (mode > 0 ? c <= 0 : c >= 0) best = i;
-        else break;
-      }
-      if (best < 0) return mkErr("#N/A");
-      return frac(BigInt(best + 1));
-    },
-  },
-  CHOOSE: {
-    min: 2,
-    call: (args) => {
-      const idxN = num(args[0]());
-      if (isErr(idxN)) return idxN;
-      const idx = Math.trunc(fracToDouble(idxN));
-      if (idx < 1 || idx > args.length - 1) return mkErr("#VALUE!");
-      return args[idx]();
-    },
-  },
-  COUNT: {
-    min: 0,
-    call: (args) => {
-      const values = collectNumbers(args, false, false);
-      return isErr(values) ? values : frac(BigInt(values.length));
-    },
-  },
-  COUNTA: {
-    min: 0,
-    call: (args) => {
-      let count = 0;
-      for (const a of args) {
-        const v = a();
+      const delim = str(args[0]());
+      if (isErr(delim)) return delim;
+      const ignoreEmpty = bool(args[1]());
+      if (isErr(ignoreEmpty)) return ignoreEmpty;
+      const parts: string[] = [];
+      for (let i = 2; i < args.length; i++) {
+        const v = args[i]();
         if (isRange(v)) {
           for (let r = 0; r < v.rows; r++) {
-            for (let c = 0; c < v.cols; c++) if (v.at(r, c) !== null) count++;
+            for (let c = 0; c < v.cols; c++) {
+              const t = toText(v.at(r, c));
+              if (isErr(t)) return t;
+              if (!(ignoreEmpty && t === "")) parts.push(t);
+            }
           }
-        } else if (v !== null) {
-          count++;
+        } else {
+          const t = str(v);
+          if (isErr(t)) return t;
+          if (!(ignoreEmpty && t === "")) parts.push(t);
         }
       }
-      return frac(BigInt(count));
+      return parts.join(delim);
     },
   },
-  COUNTIF: {
+  TRIM: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const s = str(args[0]());
+      return isErr(s) ? s : s.split(" ").filter(Boolean).join(" ");
+    },
+  },
+  UPPER: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const s = str(args[0]());
+      return isErr(s) ? s : s.toUpperCase();
+    },
+  },
+  LOWER: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const s = str(args[0]());
+      return isErr(s) ? s : s.toLowerCase();
+    },
+  },
+  SUBSTITUTE: {
+    min: 3,
+    max: 4,
+    call: (args) => {
+      const text = str(args[0]());
+      if (isErr(text)) return text;
+      const oldT = str(args[1]());
+      if (isErr(oldT)) return oldT;
+      const newT = str(args[2]());
+      if (isErr(newT)) return newT;
+      if (oldT === "") return text;
+      if (args.length <= 3) return text.split(oldT).join(newT);
+      const nthArg = num(args[3]());
+      if (isErr(nthArg)) return nthArg;
+      const nth = Math.trunc(fracToDouble(nthArg));
+      let idx = -1;
+      let count = 0;
+      let pos = 0;
+      for (;;) {
+        const found = text.indexOf(oldT, pos);
+        if (found < 0) break;
+        count++;
+        if (count === nth) {
+          idx = found;
+          break;
+        }
+        pos = found + oldT.length;
+      }
+      return idx < 0 ? text : text.slice(0, idx) + newT + text.slice(idx + oldT.length);
+    },
+  },
+  REPLACE: {
+    min: 4,
+    max: 4,
+    call: (args) => {
+      const text = str(args[0]());
+      if (isErr(text)) return text;
+      const startN = num(args[1]());
+      if (isErr(startN)) return startN;
+      const lenN = num(args[2]());
+      if (isErr(lenN)) return lenN;
+      const newText = str(args[3]());
+      if (isErr(newText)) return newText;
+      const start = Math.trunc(fracToDouble(startN));
+      const len = Math.max(0, Math.trunc(fracToDouble(lenN)));
+      if (start < 1) return mkErr("#VALUE!");
+      return text.slice(0, start - 1) + newText + text.slice(start - 1 + len);
+    },
+  },
+  FIND: {
+    min: 2,
+    max: 3,
+    call: (args) => {
+      const findT = str(args[0]());
+      if (isErr(findT)) return findT;
+      const within = str(args[1]());
+      if (isErr(within)) return within;
+      const startArg = args.length > 2 ? num(args[2]()) : ONE;
+      if (isErr(startArg)) return startArg;
+      const start = Math.trunc(fracToDouble(startArg));
+      if (start < 1) return mkErr("#VALUE!");
+      const idx = within.indexOf(findT, start - 1);
+      return idx < 0 ? mkErr("#VALUE!") : frac(BigInt(idx + 1));
+    },
+  },
+  SEARCH: {
+    min: 2,
+    max: 3,
+    call: (args) => {
+      const findT = str(args[0]());
+      if (isErr(findT)) return findT;
+      const within = str(args[1]());
+      if (isErr(within)) return within;
+      const startArg = args.length > 2 ? num(args[2]()) : ONE;
+      if (isErr(startArg)) return startArg;
+      const start = Math.trunc(fracToDouble(startArg));
+      if (start < 1) return mkErr("#VALUE!");
+      const pat = wildcardToSearchRegex(findT);
+      const m = pat.exec(within.slice(start - 1));
+      return m ? frac(BigInt(m.index + start)) : mkErr("#VALUE!");
+    },
+  },
+  REPT: {
     min: 2,
     max: 2,
     call: (args) => {
-      const range = args[0]();
-      if (!isRange(range)) return mkErr("#VALUE!");
-      const crit = toScalar(args[1]());
-      if (isErr(crit)) return crit;
-      const pred = parseCriteria(crit);
-      let count = 0;
-      for (let r = 0; r < range.rows; r++) {
-        for (let c = 0; c < range.cols; c++) if (pred(range.at(r, c))) count++;
-      }
-      return frac(BigInt(count));
+      const s = str(args[0]());
+      if (isErr(s)) return s;
+      const nArg = num(args[1]());
+      if (isErr(nArg)) return nArg;
+      const n = Math.trunc(fracToDouble(nArg));
+      return n < 0 ? mkErr("#VALUE!") : s.repeat(n);
     },
   },
-  SUMIF: {
-    min: 2,
+  ISNUMBER: { min: 1, max: 1, call: (args) => isFrac(toScalar(args[0]())) },
+  ISTEXT: { min: 1, max: 1, call: (args) => typeof toScalar(args[0]()) === "string" },
+  ISBLANK: { min: 1, max: 1, call: (args) => toScalar(args[0]()) === null },
+  ISERROR: { min: 1, max: 1, call: (args) => isErr(toScalar(args[0]())) },
+  NA: { min: 0, max: 0, call: () => mkErr("#N/A") },
+  TODAY: {
+    min: 0,
+    max: 0,
+    call: () => {
+      const now = new Date();
+      const midnight = Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate());
+      return fromDouble(dateToSerial(new Date(midnight)));
+    },
+  },
+  DATE: {
+    min: 3,
     max: 3,
     call: (args) => {
-      const range = args[0]();
-      if (!isRange(range)) return mkErr("#VALUE!");
-      const crit = toScalar(args[1]());
-      if (isErr(crit)) return crit;
-      const pred = parseCriteria(crit);
-      const sumRange = args.length > 2 ? args[2]() : range;
-      if (!isRange(sumRange)) return mkErr("#VALUE!");
-      if (sumRange.rows !== range.rows || sumRange.cols !== range.cols) {
-        return mkErr("#VALUE!", "합 범위 크기가 다름");
-      }
-      let total = ZERO;
-      for (let r = 0; r < range.rows; r++) {
-        for (let c = 0; c < range.cols; c++) {
-          if (!pred(range.at(r, c))) continue;
-          const n = toNumber(sumRange.at(r, c));
-          if (isErr(n)) return n;
-          total = add(total, n);
-        }
-      }
-      return total;
+      const y = num(args[0]());
+      if (isErr(y)) return y;
+      const m = num(args[1]());
+      if (isErr(m)) return m;
+      const d = num(args[2]());
+      if (isErr(d)) return d;
+      const date = new Date(
+        Date.UTC(
+          Math.trunc(fracToDouble(y)),
+          Math.trunc(fracToDouble(m)) - 1,
+          Math.trunc(fracToDouble(d)),
+        ),
+      );
+      return fromDouble(dateToSerial(date));
+    },
+  },
+  YEAR: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const n = num(args[0]());
+      return isErr(n) ? n : frac(BigInt(serialToDate(fracToDouble(n)).getUTCFullYear()));
+    },
+  },
+  MONTH: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const n = num(args[0]());
+      return isErr(n) ? n : frac(BigInt(serialToDate(fracToDouble(n)).getUTCMonth() + 1));
+    },
+  },
+  DAY: {
+    min: 1,
+    max: 1,
+    call: (args) => {
+      const n = num(args[0]());
+      return isErr(n) ? n : frac(BigInt(serialToDate(fracToDouble(n)).getUTCDate()));
     },
   },
 };
diff --git a/A00_Common/spreadsheet/spreadsheet_numfmt.ts b/A00_Common/spreadsheet/spreadsheet_numfmt.ts
index 1351fcab..b6533dff 100644
--- a/A00_Common/spreadsheet/spreadsheet_numfmt.ts
+++ b/A00_Common/spreadsheet/spreadsheet_numfmt.ts
@@ -14,6 +14,7 @@ import {
   fracToString,
   mul,
   roundAt,
+  sub,
   toInteger,
   type Frac,
 } from "@ui/sheet/ui_template_sheet_frac";
@@ -235,6 +236,130 @@ function renderNumericSection(toks: Tok[], magnitude: Frac): string {
   return out;
 }
 
+// ── 분수 형식(`0/0` · `# ?/?` · `# ??/??` · 분모 고정 `# ?/8`) ───────────────
+
+interface FracPlan {
+  prefix: Tok[];
+  wholeDigits: number; // 0 = 정수부 자리 없음(가분수로 통째)
+  sepToks: Tok[]; // 정수부 · 분자 사이 리터럴(보통 칸 하나)
+  fixedDenom: bigint | null; // null = 분모 자리표시(자동 찾기) · 있으면 그 값 고정
+  denomDigits: number; // 자동일 때 자리표시 개수(최대 분모 = 10^자리 - 1)
+  suffix: Tok[];
+}
+
+/** 슬래시 앞뒤 자리표시(0/#/?)·고정 숫자 자리를 찾음 — 없으면 분수 형식이 아님(null). */
+function detectFraction(toks: Tok[]): FracPlan | null {
+  if (toks.some((t) => t.k === "point")) return null;
+  const slashIdx = toks.findIndex((t) => t.k === "lit" && t.ch === "/");
+  if (slashIdx < 0) return null;
+
+  let i = slashIdx - 1;
+  while (i >= 0 && toks[i].k === "digit") i--;
+  const numeratorStart = i + 1;
+  if (numeratorStart === slashIdx) return null; // 분자 자리표시 없음
+
+  let j = slashIdx + 1;
+  let denomDigits = 0;
+  let fixedDigits = "";
+  let mode: "auto" | "fixed" | null = null;
+  while (j < toks.length) {
+    const t = toks[j];
+    if (t.k === "digit") {
+      if (mode === "fixed") break;
+      mode = "auto";
+      denomDigits++;
+      j++;
+      continue;
+    }
+    if (t.k === "lit" && /[0-9]/.test(t.ch)) {
+      if (mode === "auto") break;
+      mode = "fixed";
+      fixedDigits += t.ch;
+      j++;
+      continue;
+    }
+    break;
+  }
+  if (mode === null) return null;
+  const denomEnd = j;
+
+  const sepToks: Tok[] = [];
+  let k = numeratorStart - 1;
+  while (k >= 0 && toks[k].k !== "digit") {
+    sepToks.unshift(toks[k]);
+    k--;
+  }
+  let wholeDigits = 0;
+  while (k >= 0 && toks[k].k === "digit") {
+    wholeDigits++;
+    k--;
+  }
+  const prefix = wholeDigits > 0 ? toks.slice(0, k + 1) : toks.slice(0, numeratorStart);
+  if (wholeDigits === 0) sepToks.length = 0;
+
+  return {
+    prefix,
+    wholeDigits,
+    sepToks,
+    fixedDenom: mode === "fixed" ? BigInt(fixedDigits) : null,
+    denomDigits,
+    suffix: toks.slice(denomEnd),
+  };
+}
+
+/** 분모가 `maxDenom` 이하인 가장 가까운 분수(0 ≤ x) — 다 훑어봐도 999 번 안쪽(자리표시 최대 3 개). */
+function bestFraction(x: Frac, maxDenom: bigint): { num: bigint; den: bigint } {
+  let bestNum = 0n;
+  let bestDen = 1n;
+  let bestDiff: Frac | null = null;
+  for (let den = 1n; den <= maxDenom; den++) {
+    const num = toInteger(mul(x, frac(den)), "round");
+    const gap = sub(x, frac(num, den));
+    const diff = frac(gap.n < 0n ? -gap.n : gap.n, gap.d);
+    if (bestDiff === null || cmp(diff, bestDiff) < 0) {
+      bestDiff = diff;
+      bestNum = num;
+      bestDen = den;
+    }
+  }
+  return { num: bestNum, den: bestDen };
+}
+
+function renderFractionSection(plan: FracPlan, magnitude: Frac): string {
+  let whole = 0n;
+  let remainder = magnitude;
+  if (plan.wholeDigits > 0) {
+    whole = toInteger(magnitude, "trunc");
+    remainder = sub(magnitude, frac(whole));
+  }
+  let num: bigint;
+  let den: bigint;
+  if (plan.fixedDenom !== null) {
+    den = plan.fixedDenom;
+    num = toInteger(mul(remainder, frac(den)), "round");
+  } else {
+    const maxDenom = 10n ** BigInt(plan.denomDigits) - 1n;
+    const best = bestFraction(remainder, maxDenom);
+    num = best.num;
+    den = best.den;
+  }
+  if (plan.wholeDigits > 0 && den > 0n && num >= den) {
+    whole += num / den;
+    num %= den;
+  }
+  const fracText = num !== 0n ? `${num}/${den}` : "";
+
+  let out = "";
+  for (const t of plan.prefix) if (t.k === "lit") out += t.ch;
+  if (plan.wholeDigits > 0) {
+    if (whole !== 0n || fracText === "") out += whole.toString();
+    if (fracText !== "") for (const t of plan.sepToks) if (t.k === "lit") out += t.ch;
+  }
+  out += fracText;
+  for (const t of plan.suffix) if (t.k === "lit") out += t.ch;
+  return out;
+}
+
 function generalFormat(value: Frac): string {
   return fracToString(value);
 }
@@ -265,6 +390,11 @@ function formatNumber(value: Frac, code: string | undefined): FormattedText {
   if (color) extra.색 = color;
   if (fillChar) extra.채움글 = fillChar;
   const magnitude = cmp(value, ZERO) < 0 ? frac(-value.n, value.d) : value;
+  const fraction = detectFraction(toks);
+  if (fraction) {
+    const body = renderFractionSection(fraction, magnitude);
+    return { 글: (forceMinus ? "-" : "") + body, 정렬: "right", ...extra };
+  }
   if (!toks.some((t) => t.k === "digit" || t.k === "general")) {
     let out = "";
     for (const t of toks) if (t.k === "lit") out += t.ch;
diff --git a/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts b/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts
index 92972b24..129b4d08 100644
--- a/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts
+++ b/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts
@@ -111,6 +111,9 @@ fracEq(
 fracEq("ROUND", call("ROUND", n("1.155"), n(2)), "1.16"); // 분수 반올림 — 부동소수 함정 없음
 fracEq("ROUNDUP", call("ROUNDUP", n("1.001"), n(2)), "1.01");
 fracEq("ROUNDDOWN", call("ROUNDDOWN", n("1.999"), n(2)), "1.99");
+fracEq("ROUND 음수 자릿수(십의 자리)", call("ROUND", n(1234), n(-2)), "1200");
+fracEq("ROUNDUP 음수 자릿수", call("ROUNDUP", n(1234), n(-2)), "1300");
+fracEq("ROUNDDOWN 음수 자릿수", call("ROUNDDOWN", n(1234), n(-2)), "1200");
 fracEq("INT 양수", call("INT", n("8.9")), "8");
 fracEq("INT 음수(floor)", call("INT", n("-8.9")), "-9");
 fracEq("TRUNC", call("TRUNC", n("8.9")), "8");
@@ -142,6 +145,29 @@ errEq("AVERAGE 빈 값 없음", call("AVERAGE", range(1, 1, [["x"]])), "#DIV/0!"
 errEq("MOD 0 나눔", call("MOD", n(1), n(0)), "#DIV/0!");
 errEq("CEILING 부호 다름", call("CEILING", n(-2), n(1)), "#NUM!");
 
+// 2단계 첫 묶음(2026-09-27)
+fracEq("MROUND", call("MROUND", n(10), n(3)), "9");
+fracEq("MROUND 소수", call("MROUND", n("1.3"), n("0.2")), "1.4");
+errEq("MROUND 부호 다름", call("MROUND", n(10), n(-3)), "#NUM!");
+fracEq("ODD 양수", call("ODD", n("1.5")), "3");
+fracEq("ODD 짝수 정수", call("ODD", n(2)), "3");
+fracEq("ODD 0", call("ODD", n(0)), "1");
+fracEq("ODD 음수", call("ODD", n(-2)), "-3");
+fracEq("EVEN 양수", call("EVEN", n("1.5")), "2");
+fracEq("EVEN 홀수 정수", call("EVEN", n(3)), "4");
+fracEq("EVEN 음수", call("EVEN", n(-1)), "-2");
+fracEq("LOG 밑 지정", call("LOG", n(8), n(2)), "3");
+fracEq("LOG10", call("LOG10", n(100)), "2");
+fracEq("LN(1) = 0", call("LN", n(1)), "0");
+ok(
+  "EXP(1) ≈ e",
+  (() => {
+    const v = call("EXP", n(1));
+    return isFrac(v) && fracToString(v).startsWith("2.71828182845905");
+  })(),
+);
+errEq("LOG10 0 이하", call("LOG10", n(0)), "#NUM!");
+
 // ── 논리 · 글 ────────────────────────────────────────────────────────────
 
 fracEq("IF 참 값", call("IF", bl(true), n(1), n(2)), "1");
@@ -161,6 +187,22 @@ textEq("RIGHT", call("RIGHT", txt("가나다"), n(2)), "나다");
 textEq("MID", call("MID", txt("가나다라"), n(2), n(2)), "나다");
 fracEq("VALUE", call("VALUE", txt("1,234.5")), "1234.5");
 errEq("VALUE 실패", call("VALUE", txt("가나다")), "#VALUE!");
+textEq(
+  "TEXTJOIN 빈칸 건너뜀",
+  call("TEXTJOIN", txt("-"), bl(true), txt("a"), txt(""), txt("b")),
+  "a-b",
+);
+textEq("TRIM", call("TRIM", txt("  가   나  ")), "가 나");
+textEq("UPPER", call("UPPER", txt("abc")), "ABC");
+textEq("LOWER", call("LOWER", txt("ABC")), "abc");
+textEq("SUBSTITUTE 전부", call("SUBSTITUTE", txt("abcabc"), txt("a"), txt("X")), "XbcXbc");
+textEq("SUBSTITUTE 몇번째", call("SUBSTITUTE", txt("abcabc"), txt("a"), txt("X"), n(2)), "abcXbc");
+textEq("REPLACE", call("REPLACE", txt("abcdef"), n(2), n(3), txt("XYZ")), "aXYZef");
+fracEq("FIND", call("FIND", txt("c"), txt("abcabc")), "3");
+errEq("FIND 대소문자 가림", call("FIND", txt("C"), txt("abcabc")), "#VALUE!");
+fracEq("SEARCH 대소문자 안가림", call("SEARCH", txt("C"), txt("abcabc")), "3");
+fracEq("SEARCH 자리표시(*)", call("SEARCH", txt("a*c"), txt("xxabcyy")), "3");
+textEq("REPT", call("REPT", txt("ab"), n(3)), "ababab");
 
 // ── 찾기 ────────────────────────────────────────────────────────────────
 
@@ -207,6 +249,51 @@ fracEq(
   "40",
 );
 
+// 2단계 첫 묶음 — 여러 조건 · IFS 계열 · XLOOKUP
+const NAMES4 = range(1, 4, [["가", "나", "가", "다"]]);
+const AMOUNTS4 = range(1, 4, [[frac(10n), frac(20n), frac(30n), frac(40n)]]);
+const AMOUNTS4B = range(1, 4, [[frac(1n), frac(2n), frac(3n), frac(4n)]]);
+fracEq("SUMIFS 두 조건", call("SUMIFS", AMOUNTS4, NAMES4, txt("가"), AMOUNTS4B, txt(">1")), "30");
+fracEq("COUNTIFS 두 조건", call("COUNTIFS", NAMES4, txt("가"), AMOUNTS4B, txt(">1")), "1");
+fracEq("AVERAGEIF", call("AVERAGEIF", AMOUNTS4, txt(">15")), "30");
+fracEq("AVERAGEIFS", call("AVERAGEIFS", AMOUNTS4, NAMES4, txt("가")), "20");
+fracEq("MAXIFS", call("MAXIFS", AMOUNTS4, NAMES4, txt("가")), "30");
+fracEq("MINIFS", call("MINIFS", AMOUNTS4, NAMES4, txt("가")), "10");
+fracEq("IFS 처음 참", call("IFS", bl(false), n(1), bl(true), n(2), bl(true), n(3)), "2");
+textEq(
+  "SWITCH 맞음",
+  call("SWITCH", n(2), n(1), txt("one"), n(2), txt("two"), n(3), txt("three")),
+  "two",
+);
+textEq("SWITCH 기본값", call("SWITCH", n(9), n(1), txt("one"), txt("default")), "default");
+errEq("SWITCH 안 맞음(기본값 없음)", call("SWITCH", n(9), n(1), txt("one")), "#N/A");
+const XNAMES = range(1, 3, [["가", "나", "다"]]);
+const XAMOUNTS = range(1, 3, [[frac(10n), frac(20n), frac(30n)]]);
+fracEq("XLOOKUP", call("XLOOKUP", txt("나"), XNAMES, XAMOUNTS), "20");
+textEq("XLOOKUP 못찾음 대체값", call("XLOOKUP", txt("없음"), XNAMES, XAMOUNTS, txt("no")), "no");
+errEq("XLOOKUP 못찾음 기본", call("XLOOKUP", txt("없음"), XNAMES, XAMOUNTS), "#N/A");
+
+// 정보 · 날짜
+boolEq("ISNUMBER 참", call("ISNUMBER", n(5)) as boolean, true);
+boolEq("ISNUMBER 거짓(글)", call("ISNUMBER", txt("x")) as boolean, false);
+boolEq("ISTEXT 참", call("ISTEXT", txt("x")) as boolean, true);
+boolEq("ISBLANK 참", call("ISBLANK", lit(null)) as boolean, true);
+boolEq("ISBLANK 거짓(0)", call("ISBLANK", n(0)) as boolean, false);
+boolEq("ISERROR 참", call("ISERROR", lit({ error: "#DIV/0!" } as ErrorValue)) as boolean, true);
+boolEq("ISERROR 거짓", call("ISERROR", n(1)) as boolean, false);
+errEq("NA", call("NA"), "#N/A");
+{
+  const serial = call("DATE", n(2026), n(1), n(15));
+  fracEq("YEAR(DATE(2026,1,15))", call("YEAR", lit(serial)), "2026");
+  fracEq("MONTH(DATE(2026,1,15))", call("MONTH", lit(serial)), "1");
+  fracEq("DAY(DATE(2026,1,15))", call("DAY", lit(serial)), "15");
+}
+{
+  const todaySerial = call("TODAY");
+  const wantYear = new Date().getUTCFullYear();
+  fracEq("YEAR(TODAY()) = 지금 연도", call("YEAR", lit(todaySerial)), String(wantYear));
+}
+
 // ── 숫자 형식 ────────────────────────────────────────────────────────────
 
 function fmt(value: Scalar, code: string): string {
@@ -249,6 +336,16 @@ ok(
   fmt(frac(-150n, 100n), "0.00_);[Red](0.00)") === "(1.50)",
   fmt(frac(-150n, 100n), "0.00_);[Red](0.00)"),
 );
+
+// 분수 형식
+ok("분수 가분수(자동 분모)", fmt(frac(1n, 2n), "0/0") === "1/2", fmt(frac(1n, 2n), "0/0"));
+ok(
+  "분수 정수부+분자(자동 분모)",
+  fmt(frac(5n, 2n), "# ?/?") === "2 1/2",
+  fmt(frac(5n, 2n), "# ?/?"),
+);
+ok("분수 분모 고정", fmt(frac(4n, 10n), "# ?/8") === " 3/8", fmt(frac(4n, 10n), "# ?/8"));
+ok("분수 정확히 나눠떨어짐(정수만)", fmt(frac(3n), "# ?/?") === "3", fmt(frac(3n), "# ?/?"));
 ok("글자 형식 @", fmt("abc", "@@") === "abcabc", fmt("abc", "@@"));
 ok(
   "일반(General)",