burger fun / Four Fours / Solver

Make 92 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 92. 92 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 92 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 92 either — every combination was checked.

Solutions with square roots, factorials, exponents

  • 4! + 4! + 44 = 92
  • 4 × (4! - 4 / 4) = 92
  • 4! × (4 - 4 / 4!) = 92
  • 4 × (4! - .4 / .4) = 92
  • 4 × (4! - 4! / 4!) = 92

…and 48 more at this tier.

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

Make 91 with four 4s · Make 93 with four 4s

The Number Lab

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

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