Rullo

Rullo hands you a grid packed with numbers and one simple rule: each row and column must total exactly the value shown at its edge. Click any number to toggle it off — greyed-out numbers no longer count toward the sum. The trick is that removing a number from a row also removes it from its column, so every move has consequences in two directions. Boards range from a gentle 5×5 to a brain-bending 8×8, and three difficulty tiers control the number range, from single digits up to 19. Hold a number to lock it in place when you are certain it belongs. Clean design, zero clutter — just you against pure arithmetic logic.

Click a number to toggle it on or off Hold a number to lock it in place (hold again to unlock) Click a glowing sum box to lock its entire row or column Make each row and column add up to the target number