burger fun / Four Fours / Solver
Make 41 with four 4s
The classic four fours puzzle: build an expression from exactly four 4s that equals 41. 41 cannot be made with + - × ÷ alone (the solver checked every expression) — you will need to stick 4s together (like 44) or use decimals (like .4).
Solutions using only + - × ÷
No expression made of four plain 4s and + - × ÷ reaches 41 — the solver checked every possible expression.
Solutions with concatenation and decimals
(.4 + 4 × 4) / .4 = 41
Solutions with square roots, factorials, exponents
(.4 + 4 ^ sqrt(4)) / .4 = 41(.4 + sqrt(4) ^ 4) / .4 = 41(.4 + sqrt(4 ^ 4)) / .4 = 41(4! + sqrt(4)) / .4 - 4! = 41sqrt(((4 + 4)! + 4!) / 4!) = 41
…and 1 more at this tier.
7 distinct solutions found in total, after removing trivial rearrangements.
Make 40 with four 4s · Make 42 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.