Multiply by 9
Times 10, then take away the number once. 7 × 9 = 70 − 7 = 63.
How long?
Type the answer. Correct answers move on by themselves. Press Enter to skip a wrong one.
How the trick works
- Multiply the number by 10.
- Take away the number once.
Worked examples
7 × 9: first 7 × 10 = 70.
Then take away one 7: 70 − 7 = 63.
24 × 9: first 24 × 10 = 240.
Then take away one 24: 240 − 24 = 216.
56 × 9: first 56 × 10 = 560.
Then take away one 56: 560 − 56 = 504.
Practise it
Take the 1 minute drill above a few times. When you can do most of them without slowing down, try level 3, which mixes this trick with others.