AddOrSub

AddOrSub puts quick math reflexes to the test. In each round you have a limited time to click the + or − button to change the current value until it matches the target number. Miss the time limit and you lose — reach the goal to win and move to the next challenge.

Designed as a lightweight Chrome extension, AddOrSub features simple one-tap controls, short addictive rounds, and instantly replayable gameplay. It's perfect for short breaks, brain training, or casual competition. No complex rules — just fast thinking and precise timing.