 A good strategy for adding 9 is to add 10 and take away 1.

# Addition and Subtraction (Year 3)

In year 3, the first year in KS2, children will be taught the best methods to use when performing addition or subtraction problems in Maths. This will make them more confident when working out problems involving plus or minus symbols.

Addition is when you add two or more numbers together and subtraction is when you take them away. If you are having a party and know that 10 girls and 7 boys will be attending, how many prizes are you going to need? Well, 10 plus 7 is 17. You've got 20 prizes so how many will you have spare? Well, 20 minus 17 is 3. You've just worked out two problems - one addition and one subtraction. Knowing how to solve these problems is very useful in real life.

Take this year 3 quiz and find out how much you know about adding (plus) and subtracting (minus) problems.

1.
Which is the missing number: 7 + __ = 20?
10
12
13
14
One way to work this out is to take 7 away from 20 which will give you the answer 13
2.
75 subtract 40.
30
35
40
45
7 - 4 = 3 so 70 - 40 = 30
30 + 5 = 35
3.
17 take away 8.
9
10
11
12
17 - 10 = 7
7 + 2 = 9
4.
What is 78 + 56?
134
138
124
128
It might help to add the tens first and then the units
5.
Which will not total 100?
65 + 35
55 + 45
75 + 35
85 + 15
75 + 35 = 110
6.
Which is the best method of calculating 45 + 46?
Add the tens first and then the units
Count on from 45
Add the units first and then the tens
45 x 2 = 90
90 + 1 = 91
7.
17
20
21
25
A good strategy would be 8 + 10 - 1 = 17
17 + 3 = 20 plus 1 left over = 21
8.
Which is a good strategy for adding 9?
Add 20 and take away 11
Add 10 and take away 1
e.g. 35 + 9 so 35 + 10 = 45 then 45 - 1 = 44
9.
Which number sentence is incorrect?
8 + 5 = 13
13 - 5 = 8
5 + 8 = 13
8 - 5 = 13
The other number sentence that would be correct is 13 - 8 = 5
10.
What is the sum of 14 and 8?
18
20
21
22
14 + 10 = 24
24 - 2 = 22
Author:  Amanda Swift