burger fun / Four Fours / Solver

Make 19 with four 4s

The classic four fours puzzle: build an expression from exactly four 4s that equals 19. 19 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 19 — the solver checked every possible expression.

Solutions with concatenation and decimals

  • (4 + 4 - .4) / .4 = 19
  • (4 - (.4 - 4)) / .4 = 19

Solutions with square roots, factorials, exponents

  • 4! - 4 - 4 / 4 = 19
  • 4! - 4 / 4 - 4 = 19
  • 4 + 4! / .4 / 4 = 19
  • 4 + 4! / 4 / .4 = 19
  • 4! - (4 + 4 / 4) = 19

…and 76 more at this tier.

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

How 19 compares

19 has 83 distinct solutions across all three tiers — #40 most plentiful of the 95 solvable targets. Next door, 18 has 351 solutions and 20 has 1,058 solutions. The nearest impossible target is 73, 54 away — proven unreachable, not just unsolved.

If 19 went down easily, make 31 with four 4s — 9 solutions, the nearest step up in scarcity.

Make 18 with four 4s · Make 20 with four 4s

The Number Lab

Same idea, different constraints: four 9s, four 4s, or any four digits you like.

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.