burger fun / Four Fours / Solver

Make 1 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 1. 1 can be made with nothing but four 4s, + - × ÷, and parentheses.

Solutions using only + - × ÷

  • 4 × 4 / 4 / 4 = 1
  • 4 + 4 / 4 - 4 = 1
  • 4 - 4 + 4 / 4 = 1
  • 4 / 4 × 4 / 4 = 1
  • (4 + 4 - 4) / 4 = 1

…and 11 more at this tier.

Solutions with concatenation and decimals

  • 44 / 44 = 1
  • .44 / .44 = 1
  • 4.4 / 4.4 = 1
  • .4 × 4 / .4 / 4 = 1
  • .4 × 4 / 4 / .4 = 1

…and 72 more at this tier.

Solutions with square roots, factorials, exponents

  • 4 ^ 4 / 4 ^ 4 = 1
  • (44 - 44)! = 1
  • 44 ^ (4 - 4) = 1
  • .44 ^ (4 - 4) = 1
  • .4 ^ 4 / .4 ^ 4 = 1

…and 7347 more at this tier.

7445 distinct solutions found in total, after removing trivial rearrangements.

How 1 compares

1 has 7,445 distinct solutions across all three tiers — #2 most plentiful of the 95 solvable targets. 16 of them use nothing but + - × ÷. Next door, 2 has 6,903 solutions. The nearest impossible target is 73, 72 away — proven unreachable, not just unsolved.

If 1 went down easily, make 3 with four 4s — 1,012 solutions, the nearest step up in scarcity.

Make 2 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.