Decimal Division — Multiply & Divide Pathway
Dividing with decimals
- To divide by a decimal, make the divisor a whole number.
- Multiply both numbers by 10 (or 100) to remove the decimal.
- Then divide as normal.
- Example: 4.8 / 0.6 becomes 48 / 6 = 8.
Example: 7.2 / 0.4
- Step 1: Multiply both by 10: 72 / 4.
- Step 2: 4 into 7 = 1, remainder 3.
- Step 3: 4 into 32 = 8.
- Answer: 7.2 / 0.4 = 18.
Your turn
- Try: 3.6 / 0.9.
- Multiply both by 10: 36 / 9.
- 9 x 4 = 36.
- Answer: 4.
Common Mistakes to Avoid
- Moving the decimal in only one number. You must move the decimal in BOTH numbers by the same amount.
- Forgetting that moving the decimal one place is multiplying by 10, two places is multiplying by 100.
Real-Life Example
A rope is 7.2 metres long and is cut into 0.4 metre pieces. 7.2 / 0.4: multiply both by 10 to get 72 / 4 = 18 pieces.
Extra Support Hints
- Move the decimal in the divisor until it is a whole number, then move the dividend the same amount.
- Check by multiplying: 18 x 0.4 = 7.2. If it matches, you are correct.