burger fun / Four Fours / Solver

Make 56 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 56. 56 cannot be made with + - × ÷ alone (the solver checked every expression) — you will need to stick 4s together (like 44) or use decimals (like .4).

Solutions using only + - × ÷

No expression made of four plain 4s and + - × ÷ reaches 56 — the solver checked every possible expression.

Solutions with concatenation and decimals

  • 4 × (4 + 4 / .4) = 56

Solutions with square roots, factorials, exponents

  • 4! + 4! + 4 + 4 = 56
  • 4! + 4 + 4 + 4! = 56
  • 4 + 4! + 4 + 4! = 56
  • 4 + 4 + 4! + 4! = 56
  • 4! + 4 × (4 + 4) = 56

…and 96 more at this tier.

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

Make 55 with four 4s · Make 57 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.