burger fun / Four Fours / Solver

Make 49 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 49. 49 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 49 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 49 either — every combination was checked.

Solutions with square roots, factorials, exponents

  • 4! + 4! + 4 / 4 = 49
  • 4! + 4 / .4 / .4 = 49
  • (4! - 4.4) / .4 = 49
  • .4 / .4 + 4! + 4! = 49
  • 4! + 4! + 4! / 4! = 49

…and 28 more at this tier.

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

Make 48 with four 4s · Make 50 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.