burger fun / Four Fours / Solver
Make 77 with four 4s
The classic four fours puzzle: build an expression from exactly four 4s that equals 77. 77 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 77 — the solver checked every possible expression.
Solutions with concatenation and decimals
Concatenation and decimals do not help for 77 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.
How 77 compares
77 is one of only 5 targets out of 100 that four 4s cannot reach — the full list is 73, 77, 87, 93, 99. Next door, 76 has 20 solutions and 78 has just one solution.
The nearest fellow holdout is 73, also proven impossible.
Make 76 with four 4s · Make 78 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
Got what you came for?
Stay for something you did not search for.
- Four Nines — the daily sibling: 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.
Read up on the 1881 original, pick another number in the solver, or find more free math games.