Step-by-step Maths Level 3: Totals of several equal groups
Part of the Step-by-step Maths Level 3 multiplying with 2, 5 and 10 chapter. Chapter overview · whole chapter on one page
Totals of several equal groups
Find the total in each set of equal groups, then add the totals together if there are two sets.
Look at the question. Words like altogether, in all and in total mean add.
Key ideas
- Work out each set of equal groups.
- Add the totals if there are two sets.
- Altogether means add.
Method. Use repeated addition, or count in steps of the group size.
- Write 4 groups of 5 as repeated addition. Each pack or group has the same number.5 + 5 + 5 + 5
- Add them up, or count in steps. Count in 5s, 4 times.5, 10, 15, 20
- Write the answer. This is the total altogether.20
Check. Count in 5s 4 times and you reach 20.
Watch out. Multiply 4 by 5: each group is 5.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 2 groups of 5. Count in steps of the first number.5, 10 gives 10
- Find the pencils in the second set: 3 groups of 10. Count in steps of the second number.10, 20, 30 gives 30
- Add the two totals. Put the two sets together.10 + 30 = 40
- Write the answer. This is the total altogether.40
Check. Check: 10 is the first set and 30 is the second, so 10 + 30 = 40.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 3 groups of 2. Count in steps of the first number.2, 4, 6 gives 6
- Find the pencils in the second set: 2 groups of 5. Count in steps of the second number.5, 10 gives 10
- Add the two totals. Put the two sets together.6 + 10 = 16
- Write the answer. This is the total altogether.16
Check. Check: 6 is the first set and 10 is the second, so 6 + 10 = 16.
Watch out. Work out each set first. Then add the totals together.
Watch out
Watch out. Work out each set first. Do not add the groups and the sizes, such as 3 + 5.
Exam tip
Grown-up tip. Ask: “How many groups? How many in each group? Find each total, then put them together.”
Exercise 7E Practice: totals of equal groups
Non-calculatorMethod. Use repeated addition, or count in steps of the group size.
- Write 9 groups of 10 as repeated addition. Each pack or group has the same number.10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10
- Add them up, or count in steps. Count in 10s, 9 times.10, 20, 30, 40, 50, 60, 70, 80, 90
- Write the answer. This is the total altogether.90
Check. Count in 10s 9 times and you reach 90.
Watch out. Multiply 9 by 10: each group is 10.
Method. Use repeated addition, or count in steps of the group size.
- Write 7 groups of 5 as repeated addition. Each pack or group has the same number.5 + 5 + 5 + 5 + 5 + 5 + 5
- Add them up, or count in steps. Count in 5s, 7 times.5, 10, 15, 20, 25, 30, 35
- Write the answer. This is the total altogether.35
Check. Count in 5s 7 times and you reach 35.
Watch out. Multiply 7 by 5: each group is 5.
Method. Use repeated addition, or count in steps of the group size.
- Write 8 groups of 10 as repeated addition. Each pack or group has the same number.10 + 10 + 10 + 10 + 10 + 10 + 10 + 10
- Add them up, or count in steps. Count in 10s, 8 times.10, 20, 30, 40, 50, 60, 70, 80
- Write the answer. This is the total altogether.80
Check. Count in 10s 8 times and you reach 80.
Watch out. Multiply 8 by 10: each group is 10.
Method. Use repeated addition, or count in steps of the group size.
- Write 4 groups of 2 as repeated addition. Each pack or group has the same number.2 + 2 + 2 + 2
- Add them up, or count in steps. Count in 2s, 4 times.2, 4, 6, 8
- Write the answer. This is the total altogether.8
Check. Count in 2s 4 times and you reach 8.
Watch out. Multiply 4 by 2: each group is 2.
Method. Use repeated addition, or count in steps of the group size.
- Write 3 groups of 10 as repeated addition. Each pack or group has the same number.10 + 10 + 10
- Add them up, or count in steps. Count in 10s, 3 times.10, 20, 30
- Write the answer. This is the total altogether.30
Check. Count in 10s 3 times and you reach 30.
Watch out. Multiply 3 by 10: each group is 10.
Method. Use repeated addition, or count in steps of the group size.
- Write 3 groups of 2 as repeated addition. Each pack or group has the same number.2 + 2 + 2
- Add them up, or count in steps. Count in 2s, 3 times.2, 4, 6
- Write the answer. This is the total altogether.6
Check. Count in 2s 3 times and you reach 6.
Watch out. Multiply 3 by 2: each group is 2.
Method. Use repeated addition, or count in steps of the group size.
- Write 6 groups of 2 as repeated addition. Each pack or group has the same number.2 + 2 + 2 + 2 + 2 + 2
- Add them up, or count in steps. Count in 2s, 6 times.2, 4, 6, 8, 10, 12
- Write the answer. This is the total altogether.12
Check. Count in 2s 6 times and you reach 12.
Watch out. Multiply 6 by 2: each group is 2.
Method. Use repeated addition, or count in steps of the group size.
- Write 5 groups of 2 as repeated addition. Each pack or group has the same number.2 + 2 + 2 + 2 + 2
- Add them up, or count in steps. Count in 2s, 5 times.2, 4, 6, 8, 10
- Write the answer. This is the total altogether.10
Check. Count in 2s 5 times and you reach 10.
Watch out. Multiply 5 by 2: each group is 2.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 4 groups of 10. Count in steps of the first number.10, 20, 30, 40 gives 40
- Find the pencils in the second set: 5 groups of 2. Count in steps of the second number.2, 4, 6, 8, 10 gives 10
- Add the two totals. Put the two sets together.40 + 10 = 50
- Write the answer. This is the total altogether.50
Check. Check: 40 is the first set and 10 is the second, so 40 + 10 = 50.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 6 groups of 5. Count in steps of the first number.5, 10, 15, 20, 25, 30 gives 30
- Find the pencils in the second set: 3 groups of 10. Count in steps of the second number.10, 20, 30 gives 30
- Add the two totals. Put the two sets together.30 + 30 = 60
- Write the answer. This is the total altogether.60
Check. Check: 30 is the first set and 30 is the second, so 30 + 30 = 60.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 3 groups of 2. Count in steps of the first number.2, 4, 6 gives 6
- Find the pencils in the second set: 5 groups of 5. Count in steps of the second number.5, 10, 15, 20, 25 gives 25
- Add the two totals. Put the two sets together.6 + 25 = 31
- Write the answer. This is the total altogether.31
Check. Check: 6 is the first set and 25 is the second, so 6 + 25 = 31.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 4 groups of 2. Count in steps of the first number.2, 4, 6, 8 gives 8
- Find the pencils in the second set: 2 groups of 5. Count in steps of the second number.5, 10 gives 10
- Add the two totals. Put the two sets together.8 + 10 = 18
- Write the answer. This is the total altogether.18
Check. Check: 8 is the first set and 10 is the second, so 8 + 10 = 18.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 5 groups of 5. Count in steps of the first number.5, 10, 15, 20, 25 gives 25
- Find the pencils in the second set: 6 groups of 10. Count in steps of the second number.10, 20, 30, 40, 50, 60 gives 60
- Add the two totals. Put the two sets together.25 + 60 = 85
- Write the answer. This is the total altogether.85
Check. Check: 25 is the first set and 60 is the second, so 25 + 60 = 85.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 4 groups of 5. Count in steps of the first number.5, 10, 15, 20 gives 20
- Find the pencils in the second set: 4 groups of 2. Count in steps of the second number.2, 4, 6, 8 gives 8
- Add the two totals. Put the two sets together.20 + 8 = 28
- Write the answer. This is the total altogether.28
Check. Check: 20 is the first set and 8 is the second, so 20 + 8 = 28.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 3 groups of 10. Count in steps of the first number.10, 20, 30 gives 30
- Find the pencils in the second set: 6 groups of 2. Count in steps of the second number.2, 4, 6, 8, 10, 12 gives 12
- Add the two totals. Put the two sets together.30 + 12 = 42
- Write the answer. This is the total altogether.42
Check. Check: 30 is the first set and 12 is the second, so 30 + 12 = 42.
Watch out. Work out each set first. Then add the totals together.
Method. Work out each set separately, then add the two totals.
- Find the pencils in the first set: 2 groups of 2. Count in steps of the first number.2, 4 gives 4
- Find the pencils in the second set: 5 groups of 5. Count in steps of the second number.5, 10, 15, 20, 25 gives 25
- Add the two totals. Put the two sets together.4 + 25 = 29
- Write the answer. This is the total altogether.29
Check. Check: 4 is the first set and 25 is the second, so 4 + 25 = 29.
Watch out. Work out each set first. Then add the totals together.