Year 1: Doubles: two equal groups
Part of the Year 1 grouping and sharing chapter. Chapter overview · whole chapter on one page · Download worksheet (PDF) · Answers (PDF)
Doubles: two equal groups
A double is two equal groups added together. Double 3 means two groups of 3: 3 + 3 = 6.
Look at the two groups. They are the same. Double 4 is 4 + 4 = 8.
Key ideas
- A double is two equal groups.
- To double a number, add it to itself.
- Double 5 is 5 + 5 = 10.
- Doubles can help you add quickly.
Key words. Double means two of the same, so double 2 is 2 + 2.
Method. A double is two equal groups. Double 2 is 2 + 2.
- Find the two equal groups. Both groups must be the same size.2 and 2
- Add the two groups together. Add 2 + 2.2 + 2 = 4
- Write the answer. 4
Check. Count in 2s: 2, 4. Two groups of 2 make 4. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 4 is 4 + 4.
Method. A double is two equal groups. Double 4 is 4 + 4.
- Find the two equal groups. Both groups must be the same size.4 and 4
- Add the two groups together. Add 4 + 4.4 + 4 = 8
- Write the answer. 8
Check. Count in 4s: 4, 8. Two groups of 4 make 8. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 6 is 6 + 6.
Method. A double is two equal groups. Double 6 is 6 + 6.
- Find the two equal groups. Both groups must be the same size.6 and 6
- Add the two groups together. Add 6 + 6.6 + 6 = 12
- Write the answer. 12
Check. Count in 6s: 6, 12. Two groups of 6 make 12. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Watch out
Watch out: a double is two of the same number. Double 4 is 4 + 4, not 4 + 5.
Exam tip
Grown-up tip. Lay out two identical rows of buttons. Ask: “Are the rows the same? How many altogether?” Then ask your child to say the double sum out loud.
Exercise 9E Doubles
Non-calculatorKey words. Double means two of the same, so double 2 is 2 + 2.
Method. A double is two equal groups. Double 2 is 2 + 2.
- Find the two equal groups. Both groups must be the same size.2 and 2
- Add the two groups together. Add 2 + 2.2 + 2 = 4
- Write the answer. 4
Check. Count in 2s: 2, 4. Two groups of 2 make 4. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 3 is 3 + 3.
Method. A double is two equal groups. Double 3 is 3 + 3.
- Find the two equal groups. Both groups must be the same size.3 and 3
- Add the two groups together. Add 3 + 3.3 + 3 = 6
- Write the answer. 6
Check. Count in 3s: 3, 6. Two groups of 3 make 6. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 4 is 4 + 4.
Method. A double is two equal groups. Double 4 is 4 + 4.
- Find the two equal groups. Both groups must be the same size.4 and 4
- Add the two groups together. Add 4 + 4.4 + 4 = 8
- Write the answer. 8
Check. Count in 4s: 4, 8. Two groups of 4 make 8. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 1 is 1 + 1.
Method. A double is two equal groups. Double 1 is 1 + 1.
- Find the two equal groups. Both groups must be the same size.1 and 1
- Add the two groups together. Add 1 + 1.1 + 1 = 2
- Write the answer. 2
Check. Count in 1s: 1, 2. Two groups of 1 make 2. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 5 is 5 + 5.
Method. A double is two equal groups. Double 5 is 5 + 5.
- Find the two equal groups. Both groups must be the same size.5 and 5
- Add the two groups together. Add 5 + 5.5 + 5 = 10
- Write the answer. 10
Check. Count in 5s: 5, 10. Two groups of 5 make 10. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 9 is 9 + 9.
Method. A double is two equal groups. Double 9 is 9 + 9.
- Find the two equal groups. Both groups must be the same size.9 and 9
- Add the two groups together. Add 9 + 9.9 + 9 = 18
- Write the answer. 18
Check. Count in 9s: 9, 18. Two groups of 9 make 18. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 3 is 3 + 3.
Method. A double is two equal groups. Double 3 is 3 + 3.
- Find the two equal groups. Both groups must be the same size.3 and 3
- Add the two groups together. Add 3 + 3.3 + 3 = 6
- Write the answer. 6
Check. Count in 3s: 3, 6. Two groups of 3 make 6. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 7 is 7 + 7.
Method. A double is two equal groups. Double 7 is 7 + 7.
- Find the two equal groups. Both groups must be the same size.7 and 7
- Add the two groups together. Add 7 + 7.7 + 7 = 14
- Write the answer. 14
Check. Count in 7s: 7, 14. Two groups of 7 make 14. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 6 is 6 + 6.
Method. A double is two equal groups. Double 6 is 6 + 6.
- Find the two equal groups. Both groups must be the same size.6 and 6
- Add the two groups together. Add 6 + 6.6 + 6 = 12
- Write the answer. 12
Check. Count in 6s: 6, 12. Two groups of 6 make 12. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Key words. Double means two of the same, so double 5 is 5 + 5.
Method. A double is two equal groups. Double 5 is 5 + 5.
- Find the two equal groups. Both groups must be the same size.5 and 5
- Add the two groups together. Add 5 + 5.5 + 5 = 10
- Write the answer. 10
Check. Count in 5s: 5, 10. Two groups of 5 make 10. ✓
Watch out. A double is two groups of the same size. Do not add a different number.
Method. Use the double you know to help with the sum.
- Start with the double. Double 4 is 4 + 4.4 + 4 = 8
- Add one more. Four plus five is one more than four plus four.8 + 1 = 9
- Write the answer. 9
Check. Count on from 8 by one: 9. So 4 + 5 = 9. ✓
Watch out. The sum 4 + 5 is one more than 4 + 4, so the answer is one more than 8.
Method. Check the doubles of 4 and 5. Is 9 one of the answers?
- Find double 4. Four and four.4 + 4 = 8
- Find double 5. Five and five.5 + 5 = 10
- Look for 9. The answers are 8 and 10. There is no double that makes 9.8, then 10. Not 9.
- Write the answer. No. 9 cannot be made by doubling a number.
Check. Try the doubles of 1 to 5: 2, 4, 6, 8, 10. None of them is 9. ✓
Watch out. A double is always two equal groups. Check each double before you decide.