burger fun / Four Fours / Solver
Make 24 with four 4s
The classic four fours puzzle: build an expression from exactly four 4s that equals 24. 24 can be made with nothing but four 4s, + - × ÷, and parentheses.
Solutions using only + - × ÷
4 × 4 + 4 + 4 = 244 + 4 + 4 × 4 = 24
Solutions with concatenation and decimals
(4 + 4) / .4 + 4 = 244 × (4 / .4 - 4) = 24(4 / .4 - .4) / .4 = 24
Solutions with square roots, factorials, exponents
4 + 44 - 4! = 244 - 4! + 44 = 244 - (4! - 44) = 2444 - (4! - 4) = 24(4 - 4) / 4 + 4! = 24
…and 7837 more at this tier.
7847 distinct solutions found in total, after removing trivial rearrangements.
Make 23 with four 4s · Make 25 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.