Sum 20 puzzle · Rules and strategy
The Sum 20 puzzle asks you to drag a rectangle around numbers that add to a target. You cannot pick unrelated cells individually: every remaining number in the selected rectangle counts. Look for both small combinations and wider regions that total 20.
Rules and controls
Choose a nickname and difficulty, then drag a rectangular area with your mouse or finger. A total of exactly 20 removes the selected numbers and awards points. Removed cells remain empty, so later selections count only numbers still present.
A useful first strategy
Start with short horizontal or vertical combinations. After clearing cells, examine larger rectangles spanning the gaps. For a large value, work out the remainder you need. With limited time, scan the board in a consistent order instead of dwelling on one area.
Worked example
8 + 12 = 20. If another number lies inside the same rectangle, it also changes the total. Check the selection boundary and total before releasing.
Frequently asked questions
Why does a combination that seems correct not clear?
Other numbers between the ones you intended may lie inside the rectangle. This is a rectangular selection game, not an individual-cell picker; add every remaining number in the selected region.
Does sharing send my current game?
Share sends the game address in the current language. It does not copy your board, nickname or score.