burger fun / Four Nines / Solver

Make 59 with four 9s

The classic four nines puzzle: build an expression from exactly four 9s that equals 59. 59 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 9s and + - × ÷ reaches 59 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 59 either — every combination was checked.

Solutions with square roots, factorials, exponents

  • (9 × sqrt(9)! - .9) / .9 = 59
  • 9! / 9 / sqrt(9)!! + sqrt(9) = 59
  • 9! / sqrt(9)!! / 9 + sqrt(9) = 59
  • 9! / (9 × sqrt(9)!!) + sqrt(9) = 59

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

Make 58 with four 9s · Make 60 with four 9s

The Number Lab

Same idea, different constraints: four 9s, four 4s, or any four digits you like.

Play the daily Four Nines puzzle, pick another number in the solver, or find more free math games.