burger fun / Four Fours / Solver

Make 41 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 41. 41 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 41 — the solver checked every possible expression.

Solutions with concatenation and decimals

  • (.4 + 4 × 4) / .4 = 41

Solutions with square roots, factorials, exponents

  • (.4 + 4 ^ sqrt(4)) / .4 = 41
  • (.4 + sqrt(4) ^ 4) / .4 = 41
  • (.4 + sqrt(4 ^ 4)) / .4 = 41
  • (4! + sqrt(4)) / .4 - 4! = 41
  • sqrt(((4 + 4)! + 4!) / 4!) = 41

…and 1 more at this tier.

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

Make 40 with four 4s · Make 42 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.