burger fun / Four Fours / Solver

Make 98 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 98. 98 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 98 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 98 either — every combination was checked.

Solutions with square roots, factorials, exponents

  • (.4 + 4!) × 4 + .4 = 98
  • 4 × 4! + 4 - sqrt(4) = 98
  • 4 × 4! + 4 / sqrt(4) = 98
  • 4 + 4 × 4! - sqrt(4) = 98
  • 4 × (4! + sqrt(4) / 4) = 98

…and 38 more at this tier.

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

Make 97 with four 4s · Make 99 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.