Percentages from 10% and 1%

p% of n

The trick, step by step

1. 10% is a tenth: 10% of 400 = 40. 1% is a hundredth: 4.

   10% = 401% = 4

2. Split the percentage: 23% = 2 × 10% + 3 × 1%.

   2 × 403 × 4

3. Add: 80 + 12 = 92.

   92

given working answer taken away

Why it works

Percent means per hundred: 10% is ÷ 10 and 1% is ÷ 100. Any whole percentage is some tens and some ones, so it is built from those two.