Year 2: Equal groups and repeated addition
Part of the Year 2 multiplying and dividing chapter. Chapter overview · whole chapter on one page
Equal groups and repeated addition
Some things come in equal groups. Each group has the same number of things.
Look at 3 groups. Each group has 2 balls. To find the total, add 2 for each group: 2 + 2 + 2 = 6.
Adding the same number again and again is called repeated addition.
Key ideas
- Equal groups have the same number of things in each group.
- Repeated addition adds the same number again and again.
- Add one number for each group.
- Counting in steps of the same size gives the same total.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 2 apples.2 in one group
- Add the same number once for each group. There are 4 groups, so add 2 4 times.2 + 2 + 2 + 2
- Write the total. The total is 8 apples.8
Check. Count in 2s: 2, 4, 6, 8. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 5 cubes.5 in one group
- Add the same number once for each group. There are 3 groups, so add 5 3 times.5 + 5 + 5
- Write the total. The total is 15 cubes.15
Check. Count in 5s: 5, 10, 15. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 10 eggs.10 in one group
- Add the same number once for each group. There are 2 groups, so add 10 2 times.10 + 10
- Write the total. The total is 20 eggs.20
Check. Count in 10s: 10, 20. ✓
Watch out. Count the groups first. Then add one number for each group.
Watch out
Watch out: 3 groups of 2 means add 2 three times: 2 + 2 + 2 = 6. Adding only two 2s gives 4, which is wrong.
Exam tip
Grown-up tip. Put 3 cups on the table with 2 pasta shapes in each cup. Ask: “How many cups? How many in each cup? How many altogether?” Then count in 2s to check.
Exercise 3A Equal groups and repeated addition
Non-calculatorKey words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 2 biscuits.2 in one group
- Add the same number once for each group. There are 4 groups, so add 2 4 times.2 + 2 + 2 + 2
- Write the total. The total is 8 biscuits.8
Check. Count in 2s: 2, 4, 6, 8. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 4 flowers.4 in one group
- Add the same number once for each group. There are 3 groups, so add 4 3 times.4 + 4 + 4
- Write the total. The total is 12 flowers.12
Check. Count in 4s: 4, 8, 12. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 6 stars.6 in one group
- Add the same number once for each group. There are 3 groups, so add 6 3 times.6 + 6 + 6
- Write the total. The total is 18 stars.18
Check. Count in 6s: 6, 12, 18. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 2 pears.2 in one group
- Add the same number once for each group. There are 5 groups, so add 2 5 times.2 + 2 + 2 + 2 + 2
- Write the total. The total is 10 pears.10
Check. Count in 2s: 2, 4, 6, 8, 10. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 4 marbles.4 in one group
- Add the same number once for each group. There are 4 groups, so add 4 4 times.4 + 4 + 4 + 4
- Write the total. The total is 16 marbles.16
Check. Count in 4s: 4, 8, 12, 16. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 4 cubes.4 in one group
- Add the same number once for each group. There are 2 groups, so add 4 2 times.4 + 4
- Write the total. The total is 8 cubes.8
Check. Count in 4s: 4, 8. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 3 sweets.3 in one group
- Add the same number once for each group. There are 4 groups, so add 3 4 times.3 + 3 + 3 + 3
- Write the total. The total is 12 sweets.12
Check. Count in 3s: 3, 6, 9, 12. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 6 crayons.6 in one group
- Add the same number once for each group. There are 2 groups, so add 6 2 times.6 + 6
- Write the total. The total is 12 crayons.12
Check. Count in 6s: 6, 12. ✓
Watch out. Count the groups first. Then add one number for each group.
Key words. Equal groups have the same number of things in each group.
Method. Add the same number once for each group. Count the groups first.
- Look at one group. Each group has 3 stickers.3 in one group
- Add the same number once for each group. There are 5 groups, so add 3 5 times.3 + 3 + 3 + 3 + 3
- Write the total. The total is 15 stickers.15
Check. Count in 3s: 3, 6, 9, 12, 15. ✓
Watch out. Count the groups first. Then add one number for each group.
Method. Work out the total, then compare it with the claim.
- Work out the total. 4 groups of 3: add 3 4 times.3 + 3 + 3 + 3 = 12
- Compare with the claim. The claim says 12. The total is 12.12 = 12
- Write the answer. The claim is right only if the two numbers match.Yes. 4 × 3 = 12
Check. Count in 3s: 3, 6, 9, 12. ✓
Watch out. Add the same number once for each group. Do not stop early.
Method. Work out the total, then compare it with the claim.
- Work out the total. 5 groups of 2: add 2 5 times.2 + 2 + 2 + 2 + 2 = 10
- Compare with the claim. The claim says 7. The total is 10.7 ≠ 10
- Write the answer. The claim is right only if the two numbers match.No. 5 × 2 = 10
Check. Count in 2s: 2, 4, 6, 8, 10. ✓
Watch out. Add the same number once for each group. Do not stop early.
Method. Work out the total of the 3 groups first. Then take one whole group away.
- Work out the total of 3 groups of 4. Each group has 4 pencils. There are 3 groups.4 + 4 + 4 = 12
- Take one group away. Ben gives away one group of 4 pencils.12 − 4 = 8
- Write the answer. Ben has 2 groups of 4 left.8
Check. 2 groups of 4 make 8: 4 + 4 = 8. ✓
Watch out. Take away a whole group, not one pencil.