Four Nines Solver
The classic four nines problem, solved for every target from 1 to 100: take exactly four 9s and build an expression that equals your number. Pick a target to see its solutions — plain arithmetic first, then the fancier tricks. Or play the daily Four Nines puzzle.
How the tiers work
Tier 1: Basic arithmetic
+, -, ×, ÷ and parentheses — the daily game’s core rules
Tier 2: Concatenation and decimals
everything in tier 1, plus stuck-together 9s (99, 999, 9999) and decimals like .9 and 9.9
Tier 3: Advanced operators
everything in tier 2, plus square roots, factorials, and exponents — beyond the daily rules
Tiers 1 and 2 are checked exhaustively — when a page says no basic-arithmetic solution exists, that is a fact, not a shrug. Tier 3 is a bounded search, so it lists what the solver found rather than everything that could ever exist.
All 100 targets
- Make 1 with four 9s
- Make 2 with four 9s
- Make 3 with four 9s
- Make 4 with four 9s
- Make 5 with four 9s
- Make 6 with four 9s
- Make 7 with four 9s
- Make 8 with four 9s
- Make 9 with four 9s
- Make 10 with four 9s
- Make 11 with four 9s
- Make 12 with four 9s
- Make 13 with four 9s
- Make 14 with four 9s
- Make 15 with four 9s
- Make 16 with four 9s
- Make 17 with four 9s
- Make 18 with four 9s
- Make 19 with four 9s
- Make 20 with four 9s
- Make 21 with four 9s
- Make 22 with four 9s
- Make 23 with four 9s
- Make 24 with four 9s
- Make 25 with four 9s
- Make 26 with four 9s
- Make 27 with four 9s
- Make 28 with four 9s
- Make 29 with four 9s
- Make 30 with four 9s
- Make 31 with four 9s
- Make 32 with four 9s
- Make 33 with four 9s
- Make 34 with four 9s
- Make 35 with four 9s
- Make 36 with four 9s
- Make 37 with four 9s
- Make 38 with four 9s
- Make 39 with four 9s
- Make 40 with four 9s
- Make 41 with four 9s
- Make 42 with four 9s
- Make 43 with four 9s
- Make 44 with four 9s
- Make 45 with four 9s
- Make 46 with four 9s
- Make 47 with four 9s
- Make 48 with four 9s
- Make 49 with four 9s
- Make 50 with four 9s
- Make 51 with four 9s
- Make 52 with four 9s
- Make 53 with four 9s
- Make 54 with four 9s
- Make 55 with four 9s
- Make 56 with four 9s
- Make 57 with four 9s
- Make 58 with four 9s
- Make 59 with four 9s
- Make 60 with four 9s
- Make 61 with four 9s
- Make 62 with four 9s
- Make 63 with four 9s
- Make 64 with four 9s
- Make 65 with four 9s
- Make 66 with four 9s
- Make 67 with four 9s
- Make 68 with four 9s
- Make 69 with four 9s
- Make 70 with four 9s
- Make 71 with four 9s
- Make 72 with four 9s
- Make 73 with four 9s
- Make 74 with four 9s
- Make 75 with four 9s
- Make 76 with four 9s
- Make 77 with four 9s
- Make 78 with four 9s
- Make 79 with four 9s
- Make 80 with four 9s
- Make 81 with four 9s
- Make 82 with four 9s
- Make 83 with four 9s
- Make 84 with four 9s
- Make 85 with four 9s
- Make 86 with four 9s
- Make 87 with four 9s
- Make 88 with four 9s
- Make 89 with four 9s
- Make 90 with four 9s
- Make 91 with four 9s
- Make 92 with four 9s
- Make 93 with four 9s
- Make 94 with four 9s
- Make 95 with four 9s
- Make 96 with four 9s
- Make 97 with four 9s
- Make 98 with four 9s
- Make 99 with four 9s
- Make 100 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 (this page)
- 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
Find more free math games.