Multiply by 25
Divide by 4, then times 100. 36 × 25 = 9 × 100 = 900.
How long?
Type the answer. Correct answers move on by themselves. Press Enter to skip a wrong one.
How the trick works
- Divide the number by 4.
- Multiply by 100 by adding two zeros.
Worked examples
36 × 25: first 36 ÷ 4 = 9.
Then × 100: 9 × 100 = 900.
48 × 25: first 48 ÷ 4 = 12.
Then × 100: 12 × 100 = 1200.
124 × 25: first 124 ÷ 4 = 31.
Then × 100: 31 × 100 = 3100.
Practise it
Take the 1 minute drill above a few times. When you can do most of them without slowing down, try level 5, which mixes this trick with others.