How to play Mathlydoku

The rules

Fill every row and every column with 1, 2, 3, 4 — no repeats.
Bold-outlined boxes ("cages") of two or more cells each show a target number and an operator. The cells inside a cage must combine with that operator to reach the target.
Cage digits can combine in any order — e.g. a cage showing 3− could be filled {1,4} or {4,1}, whichever order fits the grid.

A worked example

4+3

7+4

2×1

2

1

3

1−2

3−4

2−4

2

3

1

2×2

1

7+4

3

The 3− cage (bottom-right of that group) has two cells — the only pair that subtracts to 3 is {1,4}. As soon as you place those two digits, you already know 1 and 4 are used up in that row and column, ruling them out of every other cell there.

Reading the clues

7+ — the cage's digits add up to 7.
3− — the two digits in the cage, in some order, subtract to 3.
6× — the cage's digits multiply to 6.
2÷ — the two digits in the cage, in some order, divide to 2.
A number with no symbol is a mystery cage (Hard puzzles only) — you work out the operation yourself.

Scoring & ranks

Easy is worth 30 points, Hard is worth 50. Each hint used costs −10, each mistake costs −4. Giving up scores 0.

NoviceAmazingGeniusMath Wiz

A completely clean solve — 0 hints, 0 mistakes — always earns Math Wiz.

The daily

One Easy and one Hard Mathlydoku ship every day — the exact same puzzles for every player worldwide, resetting at the UTC day boundary. Solve daily to build a streak, and use the Daily Archive to replay any past date you missed.