burger fun / Four Fours / Solver

Make 50 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 50. 50 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 50 — the solver checked every possible expression.

Solutions with concatenation and decimals

  • (4 + 4 × 4) / .4 = 50
  • (4 + 4) / .4 / .4 = 50
  • (4 + 4) / (.4 × .4) = 50

Solutions with square roots, factorials, exponents

  • 4! / 4 + 44 = 50
  • (44 - 4!) / .4 = 50
  • 4! / .4 - 4 / .4 = 50
  • 4 + 44 + sqrt(4) = 50
  • 4 + sqrt(4) + 44 = 50

…and 170 more at this tier.

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

Make 49 with four 4s · Make 51 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.