burger fun / Four Nines / Solver
Make 12 with four 9s
The classic four nines puzzle: build an expression from exactly four 9s that equals 12. 12 cannot be made with + - × ÷ alone (the solver checked every expression) — you will need to stick 9s together (like 99) or use decimals (like .9).
Solutions using only + - × ÷
No expression made of four plain 9s and + - × ÷ reaches 12 — the solver checked every possible expression.
Solutions with concatenation and decimals
(9 + 99) / 9 = 12(.9 + 9.9) / .9 = 12(.9 + .9 + 9) / .9 = 12
Solutions with square roots, factorials, exponents
9 × 9 / 9 + sqrt(9) = 129 + 9 × sqrt(9) / 9 = 129 + 9 + sqrt(9) - 9 = 129 + 9 - 9 + sqrt(9) = 129 + 9 / 9 × sqrt(9) = 12
…and 1173 more at this tier.
1181 distinct solutions found in total, after removing trivial rearrangements.
How 12 compares
12 has 1,181 distinct solutions across all three tiers — #8 most plentiful of all 100 targets. Next door, 11 has 215 solutions and 13 has 75 solutions.
If 12 went down easily, make 11 with four 9s — 215 solutions, the nearest step up in scarcity.
Make 11 with four 9s · Make 13 with four 9s
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 puzzle: 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.
Play the daily Four Nines puzzle, pick another number in the solver, or find more free math games.