 If you know that 22 + 8 = 30 it will help you to solve 30 - ? = 22.

# Using Facts to Solve Missing Number Problems

This Math quiz is called 'Using Facts to Solve Missing Number Problems' and it has been written by teachers to help you if you are studying the subject at elementary school. Playing educational quizzes is a fun way to learn if you are in the 1st or 2nd grade - aged 6 to 8.

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Using facts to solve problems means understanding that subtraction is the inverse of addition, and vise 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.

Can you find the missing number?

1.
What is the missing number:
20 - ? = 7
70
30
3
13
If 7 + 13 = 20, then 20 - 13 = 7
2.
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
3.
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
4.
Which number is missing:
100 - ? = 20
12
18
20
80
20 + 80 = 100 so 100 - 80 = 20
5.
Which number is missing:
? + 5 = 20
50
15
5
20
20 - 5 = 15, so 15 + 5 = 20
6.
What is the missing number:
12 + ? = 20
18
8
22
12
12 + 8 is a number pair, or bond, to 20
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
8.
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
9.
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
10.