burger fun / Four Fours / Solver

Make 38 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 38. 38 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 38 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 38 either — every combination was checked.

Solutions with square roots, factorials, exponents

  • 44 - 4! / 4 = 38
  • 4! + 4 + 4 / .4 = 38
  • 4 + 4! + 4 / .4 = 38
  • .4 × 4! × 4 - .4 = 38
  • .4 × 4 × 4! - .4 = 38

…and 49 more at this tier.

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

Make 37 with four 4s · Make 39 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.