Sum Grid Solving Tips
Sum Grid is subtraction first, logic second. Rules first? See how to play.
1. The difference tells all
Add up a line and subtract the target: that is exactly what must go. If one number equals the difference and no other combination does, cross it out and move on.
2. Big numbers decide fast
A number larger than its row target or column target must be crossed out. A number larger than the difference must be kept.
3. Cross-check both ways
A decision in a row changes what its column can still do. After each mark, look along the other line through that cell.
4. Odd and even
If the difference is odd, an odd number of odd values must be crossed out. Parity rules out many combinations at once.
5. Watch the colours
A red target means the line has gone wrong: kept numbers overshoot, or what remains cannot reach it. Undo to the last safe step rather than piling on more marks.
Frequently asked questions
Where should I start a Sum Grid puzzle?
Compare each line's full sum with its target. The difference is what must be crossed out; when only one number or one combination gives that difference, the line is solved.
Last updated 2026-10-21