Reception Maths: Doubles and near doubles
Part of the Reception Maths adding within 10 chapter. Chapter overview · whole chapter on one page
Doubles and near doubles
Leo has 4 cubes. Sam has 4 cubes too. They have two equal groups, so this is a double: 4 + 4 = 8.
A near double is one more or one less than a double. If you know 4 + 4, you can find 4 + 5 by adding one more.
Key ideas
- A double has two equal parts.
- A near double is a double plus one.
- Use the double you know to help.
Method. A double is two equal groups. Add the same number twice.
- Look at the two equal groups of 4. Both groups are the same.4 and 4
- Count on from the first group. Count on the second group, one at a time.4 + 4
- Write the answer. 8
Check. Count 4 and 4 together: 8. ✓
Watch out. When both parts are the same, it is a double.
Method. A near double is a double plus one. Use 4 + 4 and then add one more.
- Think of 4 + 4. That is a double, so you know it.4 + 4 = 8
- Add one more. The second number is one more, so add one.8 + 1 = 9
- Write the answer. 9
Check. Count 4 and 5 together: 9. ✓
Watch out. Use the double you know, then add one more.
Method. A near double is a double plus one. Use 2 + 2 and then add one more.
- Think of 2 + 2. That is a double, so you know it.2 + 2 = 4
- Add one more. The second number is one more, so add one.4 + 1 = 5
- Write the answer. 5
Check. Count 2 and 3 together: 5. ✓
Watch out. Use the double you know, then add one more.
Watch out
Watch out: a near double is one more than the double, not two more. Check by counting on one.
Exam tip
Grown-up tip. Make two equal rows with four buttons each. Ask your child to add one more button to one row. Ask: “How many now?”
Exercise 5D Doubles and near doubles
Non-calculatorMethod. A double is two equal groups. Add the same number twice.
- Look at the two equal groups of 2. Both groups are the same.2 and 2
- Count on from the first group. Count on the second group, one at a time.2 + 2
- Write the answer. 4
Check. Count 2 and 2 together: 4. ✓
Watch out. When both parts are the same, it is a double.
Method. A double is two equal groups. Add the same number twice.
- Look at the two equal groups of 3. Both groups are the same.3 and 3
- Count on from the first group. Count on the second group, one at a time.3 + 3
- Write the answer. 6
Check. Count 3 and 3 together: 6. ✓
Watch out. When both parts are the same, it is a double.
Method. A double is two equal groups. Add the same number twice.
- Look at the two equal groups of 5. Both groups are the same.5 and 5
- Count on from the first group. Count on the second group, one at a time.5 + 5
- Write the answer. 10
Check. Count 5 and 5 together: 10. ✓
Watch out. When both parts are the same, it is a double.
Method. A double is two equal groups. Add the same number twice.
- Look at the two equal groups of 4. Both groups are the same.4 and 4
- Count on from the first group. Count on the second group, one at a time.4 + 4
- Write the answer. 8
Check. Count 4 and 4 together: 8. ✓
Watch out. When both parts are the same, it is a double.
Method. A double is two equal groups. Add the same number twice.
- Look at the two equal groups of 1. Both groups are the same.1 and 1
- Count on from the first group. Count on the second group, one at a time.1 + 1
- Write the answer. 2
Check. Count 1 and 1 together: 2. ✓
Watch out. When both parts are the same, it is a double.
Method. A near double is a double plus one. Use 4 + 4 and then add one more.
- Think of 4 + 4. That is a double, so you know it.4 + 4 = 8
- Add one more. The second number is one more, so add one.8 + 1 = 9
- Write the answer. 9
Check. Count 4 and 5 together: 9. ✓
Watch out. Use the double you know, then add one more.
Method. A near double is a double plus one. Use 3 + 3 and then add one more.
- Think of 3 + 3. That is a double, so you know it.3 + 3 = 6
- Add one more. The second number is one more, so add one.6 + 1 = 7
- Write the answer. 7
Check. Count 3 and 4 together: 7. ✓
Watch out. Use the double you know, then add one more.
Method. A near double is a double plus one. Use 2 + 2 and then add one more.
- Think of 2 + 2. That is a double, so you know it.2 + 2 = 4
- Add one more. The second number is one more, so add one.4 + 1 = 5
- Write the answer. 5
Check. Count 2 and 3 together: 5. ✓
Watch out. Use the double you know, then add one more.
Method. A double is two equal groups. Add the same number twice.
- Look at the two equal groups of 4. Both groups are the same.4 and 4
- Count on from the first group. Count on the second group, one at a time.4 + 4
- Write the answer. 8
Check. Count 4 and 4 together: 8. ✓
Watch out. When both parts are the same, it is a double.
Method. A near double is a double plus one. Use 3 + 3 and then add one more.
- Think of 3 + 3. That is a double, so you know it.3 + 3 = 6
- Add one more. The second number is one more, so add one.6 + 1 = 7
- Write the answer. 7
Check. Count 3 and 4 together: 7. ✓
Watch out. Use the double you know, then add one more.
Method. A double has two equal parts. A near double has parts that are one apart.
- Look at 4 + 4. Both parts are 4, so it is a double.4 = 4
- Look at 4 + 5. The parts are 4 and 5, one apart, so it is a near double.5 = 4 + 1
- Write the answer. Yes, 4 + 4 is a double. 4 + 5 is a near double, because it is one more than 4 + 4.
Check. 4 + 4 = 8, and 4 + 5 = 9. ✓
Watch out. Both parts of a double are the same number.
Method. Use the double 4 + 4 = 8, then take one away for 4 + 3.
- Think of 4 + 4. That is a double, which is 8.4 + 4 = 8
- Compare 4 + 3. The second number is one less than 4, so the total is one less.8 − 1 = 7
- Write the answer. 4 + 3 is 7, because 4 + 4 is 8 and 4 + 3 is one less.
Check. Count 4 + 3 on: 5, 6, 7. ✓
Watch out. Start from the double you know.