burger fun / Four Fours / Solver

Make 11 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 11. 11 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 11 — the solver checked every possible expression.

Solutions with concatenation and decimals

  • 4 / .4 + 4 / 4 = 11
  • .4 / .4 + 4 / .4 = 11

Solutions with square roots, factorials, exponents

  • 4! / .4 / 4 - 4 = 11
  • 4! / 4 / .4 - 4 = 11
  • (4 + 4!) / 4 + 4 = 11
  • 4! / 4! + 4 / .4 = 11
  • (4! + 4! - 4) / 4 = 11

…and 122 more at this tier.

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

Make 10 with four 4s · Make 12 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.