Grades 2–3
Divide by 5 and 10 from Groups of Ten
Dividing by 10 drops a zero. Dividing by 5 is double that result, because 5 is half of 10.
A number that ends in zero is made of tens. 40 is 4 tens. Dividing by 10 asks how many tens that is, so you drop the final zero: 40 ÷ 10 = 4. Five is half of ten, so each ten holds two fives. The ÷5 answer is double the ÷10 answer.
40 ÷ 10 = 4, by dropping the zero. Then 40 ÷ 5 is double 4, which is 8. Check by counting fives: 5, 10, 15, 20, 25, 30, 35, 40 is eight fives. Or multiply back: 5 × 8 = 40.
- If the number ends in zero, drop one zero to divide by 10.
- Double that result to divide the same number by 5.
- Check by counting in fives, or by multiplying the answer by 5.
- Only drop a zero for ÷10. ÷5 keeps the zero and doubles.
60 ÷ 10 = 6, so 60 ÷ 5 = 12. 80 ÷ 10 = 8, so 80 ÷ 5 = 16. 30 ÷ 10 = 3, so 30 ÷ 5 = 6. 100 ÷ 10 = 10, so 100 ÷ 5 = 20.
Watch out
- Dropping a zero when dividing by 5. 40 ÷ 5 is 8, not 4.
- Halving the ÷10 answer instead of doubling it.
- Dropping more than one zero when the number ends in a single zero.
What is 60 ÷ 5?
60 ÷ 10 = 6, and double 6 is 12. 60 ÷ 5 = 12. Check: 5 × 12 = 60.
What is 80 ÷ 5?
80 ÷ 10 = 8, and double 8 is 16. 80 ÷ 5 = 16.
Math practice for Divide by 5 and 10
Divide by 5
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