Cross Numbers Solver

Cross Numbers Solver — Step by Step

This solver explains puzzles sent from the game with Send to Solver. Press Sample for another puzzle, then Solve. Or play a generated puzzle and send it here with one click.

Cross Numbers Solver: rules, how to use it, tips

Fill the grid with numbers so every across and down answer fits its maths clue, sharing digits where answers cross.

The rules

Each white square holds one digit; each answer reads across or down.
No answer starts with 0.
Clues describe the number (a square, a prime, a multiple of 7, its digit sum…) or link it to another answer.
Where answers cross they share the same digit.

Using the solver

Send a puzzle from the game, or press Sample.
Press Solve and step through: the numbers each clue allows, and how the crossings and links pin each answer down.

Tips

Short and special. Two-digit squares (16, 25, 36, 49, 64, 81) and cubes (27, 64) give very few options — start there.
Use the crossings. If 1 Across must start with 1, 2, 3 or 4 and 1 Down starts with the same square, 1 Down’s options shrink too.
Digit sums. ‘Digits add up to 3’ for a 3-digit number allows only 102, 111, 120, 201, 210 and 300.
Multiples. Multiples of 5 end in 0 or 5; multiples of 9 have digits adding to a multiple of 9.

The full guide, with a worked example and common mistakes: How to play Cross Numbers.

Questions

What does ‘3 Down × 4 − 2’ mean?

Take the answer to 3 Down, multiply by 4, then subtract 2 — that’s this answer.

What is a palindrome?

A number that reads the same both ways, like 4554 or 121.

Is there always one answer?

Yes — every puzzle here is checked to have exactly one solution.

Can I enter a puzzle from a book?

The solver explains puzzles made here; it can’t read printed clues, but any generated puzzle can be sent to it.