burger fun / Four Fours / Solver
Make 5 with four 4s
The classic four fours puzzle: build an expression from exactly four 4s that equals 5. 5 can be made with nothing but four 4s, + - × ÷, and parentheses.
Solutions using only + - × ÷
(4 + 4 × 4) / 4 = 5
Solutions with concatenation and decimals
(4 + 4) / .4 / 4 = 5(4 + 4) / 4 / .4 = 5(4 - .4) / .4 - 4 = 5(.4 + .4 × 4) / .4 = 5(4 + 4) / (.4 × 4) = 5
…and 2 more at this tier.
Solutions with square roots, factorials, exponents
4! / 4 - 4 / 4 = 5(4 / 4) ^ 4 + 4 = 5(44 - 4!) / 4 = 54 + 4 ^ (4 - 4) = 5(4 - 4)! ^ 4 + 4 = 5
…and 1397 more at this tier.
1410 distinct solutions found in total, after removing trivial rearrangements.
How 5 compares
5 has 1,410 distinct solutions across all three tiers — #9 most plentiful of the 95 solvable targets. Exactly one of them uses nothing but + - × ÷. Next door, 4 has 4,999 solutions and 6 has 2,667 solutions. The nearest impossible target is 73, 68 away — proven unreachable, not just unsolved.
If 5 went down easily, make 7 with four 4s — 176 solutions, the nearest step up in scarcity.
Make 4 with four 4s · Make 6 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
Got what you came for?
Stay for something you did not search for.
- Four Nines — the daily sibling: four 9s, one target, new at midnight
- The Reflex Lab — nine ways to measure your hands and memory, none of them polite about it
- hand me something weird — a random pick from the directory. Could be the horse.
Read up on the 1881 original, pick another number in the solver, or find more free math games.