Goal
Fill every white cell with a digit from 1 to 9 so each run adds up to its clue.
Number game
Runsums
Make every run add up to its clue.
Play Runsums on brainstretch.
- difficulty
- Easy – Expert
- one player
- Solo
- needed to play
- No account
- when you are stuck
- Hints
How to play Runsums
Runs.
A run is a line of white cells, across or down, that starts next to a clue.
Clues.
The number above the diagonal is the sum of the run going across. The number below it is the sum of the run going down.
4
3
3
4
The clues
→
4
3
3
12
4
31
The answer
No repeats.
A digit is used once in a run. It may come back in another run, even in the same row.
One answer.
Every board has exactly one answer, and you can reach it without guessing.
Start here.
In the example, 3 in two cells can only be 1 + 2, and 4 in two cells can only be 1 + 3. The top-left cell is in both runs, and only 1 is in both sets, so it is 1. Then each run has one cell left.
Controls
Tap a white cell, then a digit. Notes switches the keypad to pencil marks. On a keyboard, the arrow keys move, 1 to 9 enter a digit, Backspace erases and N switches notes.
