Make 8 with four 9s

The classic four nines puzzle: build an expression from exactly four 9s that equals 8. 8 can be made with nothing but four 9s, + - × ÷, and parentheses.

Solutions using only + - × ÷

(9 × 9 - 9) / 9 = 8

Solutions with concatenation and decimals

9 + 9 - 9 / .9 = 8
.9 × 9 - .9 / 9 = 8
9 - .9 - .9 / 9 = 8
9 - .9 / 9 - .9 = 8
9 - (9 / .9 - 9) = 8

…and 4 more at this tier.

Solutions with square roots, factorials, exponents

9 - (9 / 9) ^ 9 = 8
9 - 9 ^ (9 - 9) = 8
9 - (9 - 9)! ^ 9 = 8
9 - .9 ^ (9 - 9) = 8
9 - 9! ^ (9 - 9) = 8

…and 701 more at this tier.

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

Make 7 with four 9s · Make 9 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.