Make 87 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 87. 87 cannot be made from four 4s at all under these rules — tiers 1 and 2 are proven exhaustively, and the bounded tier-3 search came up empty too.

Solutions using only + - × ÷

No expression made of four plain 4s and + - × ÷ reaches 87 — the solver checked every possible expression.

Solutions with concatenation and decimals

Concatenation and decimals do not help for 87 either — every combination was checked.

Solutions with square roots, factorials, exponents

No solution found at this tier within the solver’s search bounds — square roots, factorials, and exponents all come up empty.

Zero solutions found. Not for lack of trying — the solver tried everything its rules allow.

Make 86 with four 4s · Make 88 with four 4s

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

Read up on the 1881 original, pick another number in the solver, or find more free math games.