Step-by-step Maths Level 3 Multiplying with 2, 5 and 10: check-up and practice test questions

Method. Use the 2, 5 or 10 facts. Count in steps of the number to find the missing number.

1. Count in 10s until you reach 70. Each count is one group.
   10, 20, 30, 40, 50, 60, 70
2. Count the numbers you said. There are 7 numbers, so there are 7 groups.
   7 groups
3. Write the answer. This is the number of groups.
   7

Check. Check: 10 × 7 = 70.

Watch out. The times table of 10 is the key. Division is the opposite of multiplication.

Method. Use the 2, 5 or 10 facts. Count in steps of the number to find the missing number.

1. Think of the multiplication: 5 × ? = 50. Division asks how many groups.
   5 × ? = 50
2. Count in 5s until you reach 50. Count the steps as you go.
   5, 10, 15, 20, 25, 30, 35, 40, 45, 50
3. Write the answer. This is the number of groups.
   10

Check. Check: 5 × 10 = 50, so 50 ÷ 5 = 10.

Watch out. The times table of 5 is the key. Division is the opposite of multiplication.

Method. Count in 10s to find 10 groups of 10. The order of the two numbers does not matter.

1. Count in 10s, 10 times. Each count adds one more group of 10.
   10, 20, 30, 40, 50, 60, 70, 80, 90, 100
2. The last number we said is the answer. We counted in equal groups.
   10 × 10 = 100
3. Write the answer. The order of the numbers does not change the answer.
   100

Check. Check: 10 × 10 is also 100.

Watch out. Say the 10 times table in order until you reach the fact you need.

Method. Use repeated addition, or count in steps of the group size.

1. Write 4 groups of 10 as repeated addition. Each pack or group has the same number.
   10 + 10 + 10 + 10
2. Add them up, or count in steps. Count in 10s, 4 times.
   10, 20, 30, 40
3. Write the answer. This is the total altogether.
   40

Check. Count in 10s 4 times and you reach 40.

Watch out. Multiply 4 by 10: each group is 10.

Method. Count in 2s to find 2 groups of 12. The order of the two numbers does not matter.

1. Count in 2s, 12 times. Each count adds one more group of 2.
   2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24
2. The last number we said is the answer. We counted in equal groups.
   2 × 12 = 24
3. Write the answer. The order of the numbers does not change the answer.
   24

Check. Check: 12 × 2 is also 24.

Watch out. Say the 2 times table in order until you reach the fact you need.

Method. Count in 5s to find 5 groups of 6. The order of the two numbers does not matter.

1. Count in 5s, 6 times. Each count adds one more group of 5.
   5, 10, 15, 20, 25, 30
2. The last number we said is the answer. We counted in equal groups.
   5 × 6 = 30
3. Write the answer. The order of the numbers does not change the answer.
   30

Check. Check: 6 × 5 is also 30.

Watch out. Say the 5 times table in order until you reach the fact you need.

Method. Count in 2s to find 2 groups of 7. The order of the two numbers does not matter.

1. Count in 2s, 7 times. Each count adds one more group of 2.
   2, 4, 6, 8, 10, 12, 14
2. The last number we said is the answer. We counted in equal groups.
   2 × 7 = 14
3. Write the answer. The order of the numbers does not change the answer.
   14

Check. Check: 7 × 2 is also 14.

Watch out. Say the 2 times table in order until you reach the fact you need.

Method. Use the 2, 5 or 10 facts. Count in steps of the number to find the missing number.

1. Count in 10s until you reach 30. Each count is one group.
   10, 20, 30
2. Count the numbers you said. There are 3 numbers, so there are 3 groups.
   3 groups
3. Write the answer. This is the number of groups.
   3

Check. Check: 10 × 3 = 30.

Watch out. The times table of 10 is the key. Division is the opposite of multiplication.

Method. Count in 10s to find 10 groups of 6. The order of the two numbers does not matter.

1. Count in 10s, 6 times. Each count adds one more group of 10.
   10, 20, 30, 40, 50, 60
2. The last number we said is the answer. We counted in equal groups.
   10 × 6 = 60
3. Write the answer. The order of the numbers does not change the answer.
   60

Check. Check: 6 × 10 is also 60.

Watch out. Say the 10 times table in order until you reach the fact you need.

Method. Count in 5s to find 5 groups of 4. The order of the two numbers does not matter.

1. Count in 5s, 4 times. Each count adds one more group of 5.
   5, 10, 15, 20
2. The last number we said is the answer. We counted in equal groups.
   5 × 4 = 20
3. Write the answer. The order of the numbers does not change the answer.
   20

Check. Check: 4 × 5 is also 20.

Watch out. Say the 5 times table in order until you reach the fact you need.

Method. Count in 5s to find 5 groups of 6. The order of the two numbers does not matter.

1. Count in 5s, 6 times. Each count adds one more group of 5.
   5, 10, 15, 20, 25, 30
2. The last number we said is the answer. We counted in equal groups.
   5 × 6 = 30
3. Write the answer. The order of the numbers does not change the answer.
   30

Check. Check: 6 × 5 is also 30.

Watch out. Say the 5 times table in order until you reach the fact you need.

Method. Use repeated addition, or count in steps of the group size.

1. Write 9 groups of 2 as repeated addition. Each pack or group has the same number.
   2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2
2. Add them up, or count in steps. Count in 2s, 9 times.
   2, 4, 6, 8, 10, 12, 14, 16, 18
3. Write the answer. This is the total altogether.
   18

Check. Count in 2s 9 times and you reach 18.

Watch out. Multiply 9 by 2: each group is 2.

Method. Count in 10s to find 10 groups of 9. The order of the two numbers does not matter.

1. Count in 10s, 9 times. Each count adds one more group of 10.
   10, 20, 30, 40, 50, 60, 70, 80, 90
2. The last number we said is the answer. We counted in equal groups.
   10 × 9 = 90
3. Write the answer. The order of the numbers does not change the answer.
   90

Check. Check: 9 × 10 is also 90.

Watch out. Say the 10 times table in order until you reach the fact you need.

Method. Count in 2s to find 2 groups of 4. The order of the two numbers does not matter.

1. Count in 2s, 4 times. Each count adds one more group of 2.
   2, 4, 6, 8
2. The last number we said is the answer. We counted in equal groups.
   2 × 4 = 8
3. Write the answer. The order of the numbers does not change the answer.
   8

Check. Check: 4 × 2 is also 8.

Watch out. Say the 2 times table in order until you reach the fact you need.

Method. Count in 2s to find 2 groups of 8. The order of the two numbers does not matter.

1. Count in 2s, 8 times. Each count adds one more group of 2.
   2, 4, 6, 8, 10, 12, 14, 16
2. The last number we said is the answer. We counted in equal groups.
   2 × 8 = 16
3. Write the answer. The order of the numbers does not change the answer.
   16

Check. Check: 8 × 2 is also 16.

Watch out. Say the 2 times table in order until you reach the fact you need.

Method. Count in 5s to find 5 groups of 2. The order of the two numbers does not matter.

1. Count in 5s, 2 times. Each count adds one more group of 5.
   5, 10
2. The last number we said is the answer. We counted in equal groups.
   5 × 2 = 10
3. Write the answer. The order of the numbers does not change the answer.
   10

Check. Check: 2 × 5 is also 10.

Watch out. Say the 5 times table in order until you reach the fact you need.

Method. Count in 5s to find 5 groups of 4. The order of the two numbers does not matter.

1. Count in 5s, 4 times. Each count adds one more group of 5.
   5, 10, 15, 20
2. The last number we said is the answer. We counted in equal groups.
   5 × 4 = 20
3. Write the answer. The order of the numbers does not change the answer.
   20

Check. Check: 4 × 5 is also 20.

Watch out. Say the 5 times table in order until you reach the fact you need.

Method. Count in 5s to find 5 groups of 4. The order of the two numbers does not matter.

1. Count in 5s, 4 times. Each count adds one more group of 5.
   5, 10, 15, 20
2. The last number we said is the answer. We counted in equal groups.
   5 × 4 = 20
3. Write the answer. The order of the numbers does not change the answer.
   20

Check. Check: 4 × 5 is also 20.

Watch out. Say the 5 times table in order until you reach the fact you need.

Method. Use the 2, 5 or 10 facts. Count in steps of the number to find the missing number.

1. Think: how many groups of 5 make 40? Count in steps of the first number.
   5, 10, 15, 20, 25, 30, 35, 40
2. Count the groups. We said 8 numbers, so there are 8 groups.
   8 groups of 5
3. Write the missing number. This is the number of groups.
   8

Check. Check: 5 × 8 = 40.

Watch out. The times table of 5 is the key. Division is the opposite of multiplication.

Method. Count in 10s to find 10 groups of 12. The order of the two numbers does not matter.

1. Count in 10s, 12 times. Each count adds one more group of 10.
   10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120
2. The last number we said is the answer. We counted in equal groups.
   10 × 12 = 120
3. Write the answer. The order of the numbers does not change the answer.
   120

Check. Check: 12 × 10 is also 120.

Watch out. Say the 10 times table in order until you reach the fact you need.