burger fun / Four Fours / Solver
Make 64 with four 4s
The classic four fours puzzle: build an expression from exactly four 4s that equals 64. 64 can be made with nothing but four 4s, + - × ÷, and parentheses.
Solutions using only + - × ÷
(4 + 4) × (4 + 4) = 64
Solutions with square roots, factorials, exponents
4! + 44 - 4 = 644! - 4 + 44 = 644! + 4! + 4 × 4 = 644! + 4 × 4 / .4 = 644! - (4 - 44) = 64
…and 705 more at this tier.
711 distinct solutions found in total, after removing trivial rearrangements.
Make 63 with four 4s · Make 65 with four 4s
The Number Lab
Same idea, different constraints: four 9s, four 4s, or any four digits you like.
- Four Nines — the daily puzzle
- Four Nines solver — every target, solved
- Four Fours — the 1881 original
- Four Fours solver — including the impossible five
- Make 24 solver — any four digits
- Today's 24 — one new hand a day
Read up on the 1881 original, pick another number in the solver, or find more free math games.