All four operations, step by step
The last step in fact fluency is a page that gives no clue about which operation is coming next.
The question
30 ÷ 10
30÷10
10×?=30
10×3=30
30÷10=3
3×10=30
- 30 ÷ 10 means sharing 30 out equally between 10. Deal them round one at a time until they run out; the answer is how many end up in one share.
- Dealing out 30 one at a time works, and takes all day. The shortcut is the same fact read backwards: 10 shares of WHAT makes 30?
- 10 × 3 = 30. That is the one, so 30 ÷ 10 = 3.
- Worth checking, because it costs one multiplication: 3 × 10 = 30. It matches, so the answer holds.
How it works.
- 01
30 ÷ 10 means sharing 30 out equally between 10. Deal them round one at a time until they run out; the answer is how many end up in one share.
- 02
Dealing out 30 one at a time works, and takes all day. The shortcut is the same fact read backwards: 10 shares of WHAT makes 30?
- 03
10 × 3 = 30. That is the one, so 30 ÷ 10 = 3.
- 04
Worth checking, because it costs one multiplication: 3 × 10 = 30. It matches, so the answer holds.