ARITH · WORKED EXAMPLES

Mental math for a crowded screen

A busy arith screen makes it tempting to guess. These methods reduce the amount you need to remember, using the addition and subtraction expressions that actually appear in the game.

Split the second number

For 47 + 28, add the tens first: 47 + 20 = 67. Then add the units: 67 + 8 = 75. You hold one running total instead of trying to perform both columns at once. The same method works for subtraction: 83 − 26 becomes 83 − 20 = 63, then 63 − 6 = 57.

Round, then compensate

When a number is close to a multiple of ten, temporarily use the easier number. For 68 + 29, add 30 to get 98, then subtract the extra 1: 97. For 92 − 38, subtract 40 to get 52, then put back the extra 2 you removed: 54.

The direction matters. Adding too much needs a subtraction afterward. Subtracting too much needs an addition afterward. If you are unsure, use the split-number method instead of guessing which correction to make.

Group terms without losing their signs

For 46 + 27 − 16, combine 46 − 16 first to make 30; then add 27 to get 57. You may rearrange addition and subtraction by treating each term as a signed number: +46, +27, and −16. Move the sign with its number. Changing the example to 46 − 27 + 16 changes the answer.

Recognize a family of questions

When several questions happen to share a pattern, use it to check your arithmetic. For example, in 34 + 11, 34 + 13, and 34 + 15, the answers are 45, 47, and 49. The game releases questions at random, so patterns are occasional rather than a scheduled sequence. Each answer still needs its own shot, and another visitor may destroy a comet while you calculate.

Subtraction reverses the answer pattern. The answers to 34 − 11, 34 − 13, and 34 − 15 are 23, 21, and 19. Increasing the amount subtracted decreases the result.

Try these before starting a round

1. 56 + 37
2. 81 − 29
3. 64 + 18 − 24
4. 72 − 16, 72 − 19, 72 − 22

Choose one method for your next round. Afterward, write down one expression you missed and solve it slowly. This is a practice suggestion, not a claim that a game score measures mathematical ability.

Try a round

Read the controls and ammunition guide if you are new.