Subtract from 1000
Take every digit from 9 and the last one from 10. 1000 − 374 = 626.
How long?
Type the answer. Correct answers move on by themselves. Press Enter to skip a wrong one.
How the trick works
- Write the number with three digits.
- Take the first two digits from 9.
- Take the last digit from 10.
Worked examples
1000 − 374: take each digit from 9, except the last from 10.
9 − 3 = 6, 9 − 7 = 2, 10 − 4 = 6, so 626.
1000 − 658: take each digit from 9, except the last from 10.
9 − 6 = 3, 9 − 5 = 4, 10 − 8 = 2, so 342.
1000 − 281: take each digit from 9, except the last from 10.
9 − 2 = 7, 9 − 8 = 1, 10 − 1 = 9, so 719.
Practise it
Take the 1 minute drill above a few times. When you can do most of them without slowing down, try level 4, which mixes this trick with others.