burger fun / Four Fours / Solver

Make 75 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 75. 75 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 75 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 75 either — every combination was checked.

Solutions with square roots, factorials, exponents

  • (4! + 4! / 4) / .4 = 75
  • (4! / 4)! / .4 / 4! = 75
  • (4! / 4)! / 4! / .4 = 75
  • 4! / (.4 + .4) / .4 = 75
  • 4! / .4 / (.4 + .4) = 75

…and 26 more at this tier.

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

How 75 compares

75 has 31 distinct solutions across all three tiers — #32 scarcest of the 95 solvable targets. Next door, 74 has 10 solutions and 76 has 20 solutions. The nearest impossible target is 73, 2 away — proven unreachable, not just unsolved.

If 75 went down easily, make 74 with four 4s — 10 solutions, the nearest step up in scarcity.

Make 74 with four 4s · Make 76 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.