*This quiz addresses the requirements of the National Curriculum KS1 Maths and Numeracy for children aged 6 and 7 in year 2. Specifically this quiz is aimed at the section dealing with using known facts to solve missing number problems. *

Using facts to solve problems means understanding that subtraction is the inverse of addition, and vice versa. Therefore, if you know that 6 + 4 = 10, you could find the missing number in 10 - ? = 4 by using the same numbers.

This quiz will help your child to solve missing number problems by using number facts known to them.

Question 1

Which number is missing:

? + 5 = 20

? + 5 = 20

50

15

5

20

20 - 5 = 15, so 15 + 5 = 20

Question 2

If 95 + 5 = 100 is true, which of the following is not true?

95 + 95 = 100

5 + 95 = 100

100 - 95 = 5

100 - 5 = 95

The numbers in each calculation should always be 5, 95 and 100

Question 3

You could use 100 - 25 = 75 to help you solve:

25 + 75

75 - 25

75 - 100

25 - 100

If you know that 100 - 25 = 75, then you could solve 25 + 75 = 100

Question 4

Which number is missing:

100 - ? = 20

100 - ? = 20

12

18

20

80

20 + 80 = 100 so 100 - 80 = 20

Question 5

What is the missing number:

12 + ? = 20

12 + ? = 20

18

8

22

12

12 + 8 is a number pair, or bond, to 20

Question 6

You could use 45 + 55 = 100 to help you solve:

100 - 5

40 + 500

100 - 20

100 - 55

If 45 + 55 = 100, you could solve 100 - 55 = 45

Question 7

If 16 + 84 = 100 is true, which of the following is not true?

84 + 16 = 100

100 - 84 = 16

16 + 16 = 84

100 - 16 = 84

16 + 16 = 32, not 100

Question 8

What is the missing number:

20 - ? = 7

20 - ? = 7

70

30

3

13

If 7 + 13 = 20, then 20 - 13 = 7

Question 9

Which fact would help you solve:

10 - ? = 4

10 - ? = 4

8 + 2 = 10

10 + 4 = 14

4 + 6 = 10

10 + 6 = 16

If 4 + 6 = 10, then 10 - 6 = 4

Question 10

If 15 + 85 = 100 is true, which of the following is not true?

100 - 15 = 85

100 - 85 = 100

100 - 85 = 15

85 + 15 = 100

100 - 85 = 15, not 100