Classic
The basic mode of mental math: additions and subtractions one after another. Four small numbers at the first level; with each level passed, the series gets longer and the numbers bigger. Great to warm up, and to see how you progress from one game to the next.
How to play
Add up the numbers that show. If the total is right, the next level has more of them, and bigger ones.
Example
4 − 2 + 5 − 3 = 4
Tips
- Keep a single total in mind and update it with each number, rather than remembering the series.
- Look for pairs that cancel out or make 10: + 7 then − 7 change nothing.
- Say the total under your breath: hearing it helps you hold on to it.
Solo or against someone
Solo, go as far as you can: the first mistake ends the game. Against someone, you play the same levels as your opponent: if you're the only one with the right answer, you win. All the rules