burger fun / Four Fours / Solver

Make 97 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 97. 97 cannot be made with + - × ÷, concatenation, or decimals (the solver checked every expression) — solutions need square roots, factorials, or exponents.

Solutions using only + - × ÷

No expression made of four plain 4s and + - × ÷ reaches 97 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 97 either — every combination was checked.

Solutions with square roots, factorials, exponents

  • 4 × 4! + 4 / 4 = 97
  • .4 / .4 + 4 × 4! = 97
  • 4! / 4! + 4 × 4! = 97
  • (4 - 4)! + 4 × 4! = 97
  • (.4 - .4)! + 4 × 4! = 97

…and 3 more at this tier.

8 distinct solutions found in total, after removing trivial rearrangements.

How 97 compares

97 has 8 distinct solutions across all three tiers — #19 scarcest of the 95 solvable targets. Next door, 96 has 755 solutions and 98 has 43 solutions. The nearest impossible target is 99, 2 away — proven unreachable, not just unsolved.

If 97 went down easily, make 91 with four 4s — just one solution, the nearest step up in scarcity.

Make 96 with four 4s · Make 98 with four 4s

The Number Lab

Same idea, different constraints: four 9s, four 4s, or any four digits you like.

Got what you came for?

Stay for something you did not search for.

  • Four Nines — the daily sibling: four 9s, one target, new at midnight
  • The Reflex Lab — nine ways to measure your hands and memory, none of them polite about it
  • hand me something weird — a random pick from the directory. Could be the horse.

Read up on the 1881 original, pick another number in the solver, or find more free math games.