burger fun / Four Fours / Solver
Make 17 with four 4s
The classic four fours puzzle: build an expression from exactly four 4s that equals 17. 17 can be made with nothing but four 4s, + - × ÷, and parentheses.
Solutions using only + - × ÷
4 × 4 + 4 / 4 = 17
Solutions with concatenation and decimals
.4 / .4 + 4 × 4 = 17
Solutions with square roots, factorials, exponents
(4! + 44) / 4 = 174! / 4! + 4 × 4 = 17(4 - 4)! + 4 × 4 = 174! - (4 + 4!) / 4 = 17(.4 - .4)! + 4 × 4 = 17
…and 42 more at this tier.
49 distinct solutions found in total, after removing trivial rearrangements.
How 17 compares
17 has 49 distinct solutions across all three tiers — #46 scarcest of the 95 solvable targets. Exactly one of them uses nothing but + - × ÷. Next door, 16 has 2,689 solutions and 18 has 351 solutions. The nearest impossible target is 73, 56 away — proven unreachable, not just unsolved.
If 17 went down easily, make 31 with four 4s — 9 solutions, the nearest step up in scarcity.
Make 16 with four 4s · Make 18 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.