Multiply by 5

n × 5

The trick, step by step

1. Multiply by 10 instead: 46 × 10 = 460.

   46× 10460

2. Halve it: half of 460 is 230.

   460÷ 2230

3. So 46 × 5 = 230.

given working answer taken away

Why it works

5 is half of 10, so n × 5 = n × 10 ÷ 2. Multiplying by 10 only puts a 0 on the end, and halving is easier than multiplying by 5.