burger fun / Four Nines / Solver
Make 29 with four 9s
The classic four nines puzzle: build an expression from exactly four 9s that equals 29. 29 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 29 — the solver checked every possible expression.
Solutions with concatenation and decimals
(9 + 9) / .9 + 9 = 29
Solutions with square roots, factorials, exponents
(9 × sqrt(9) - .9) / .9 = 299 + sqrt(9)! × sqrt(9) / .9 = 299 + sqrt(9) × sqrt(9)! / .9 = 29(9 × 9 + sqrt(9)!) / sqrt(9) = 29(9 + sqrt(9)! / 9) × sqrt(9) = 29
…and 18 more at this tier.
24 distinct solutions found in total, after removing trivial rearrangements.
Make 28 with four 9s · Make 30 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
Play the daily Four Nines puzzle, pick another number in the solver, or find more free math games.