Make 17 with four 9s

The classic four nines puzzle: build an expression from exactly four 9s that equals 17. 17 can be made with nothing but four 9s, + - × ÷, and parentheses.

Solutions using only + - × ÷

9 + 9 - 9 / 9 = 17
9 - (9 / 9 - 9) = 17

Solutions with concatenation and decimals

9 + 9 - .9 / .9 = 17
9 - (.9 / .9 - 9) = 17

Solutions with square roots, factorials, exponents

9 + 9 - 9! / 9! = 17
9 + 9 - (9 - 9)! = 17
9 - (9! / 9! - 9) = 17
9 + 9 - (.9 - .9)! = 17
9 + 9 - (9! - 9!)! = 17

…and 58 more at this tier.

67 distinct solutions found in total, after removing trivial rearrangements.

How 17 compares

17 has 67 distinct solutions across all three tiers — #43 most plentiful of all 100 targets. 2 of them use nothing but + - × ÷. Next door, 16 has 56 solutions and 18 has 1,302 solutions.

If 17 went down easily, make 22 with four 9s — 11 solutions, the nearest step up in scarcity.

Make 16 with four 9s · Make 18 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.