Adding in Parts

I am learning to add by splitting numbers into parts.

Example : 8 can be split into

or 2 and 6

or 3 and 5

or 4 and 4

1 and 7

SAMPLE PROBLEM

Andrew has picked 28 cherries. He picks 5 more cherries. How many cherries has he picked in total?

28 + 5 = …..

Number of cherries he had already picked.

Number of extra cherries he has just picked.

Total number of cherries he has.

SAMPLE PROBLEM

Step 1: I want to get 28 to a tidy number. The closest tidy number is 30.

28 + 5 = …..

Step 2: Now I think 28 plus what would equal 30.

28 + 2 = 30

SAMPLE PROBLEM

Step 3: I took the 2 from the five which means I have three left over.

28 + 5 = …..

5

28 + 2 = 30

2 + 3

Step 4 : We split the five into a two and a three. We added the two to get to thirty (a tidy number). Now we must add the three.

30 + 3 = 33

SAMPLE PROBLEM

Answer: 28 + 5 = 33

28 + 5 = …..

Review: So instead of adding 5 all at once

28 + 5 = …….

We split the five into two parts so that first we could make a tidy number then we added what was left over.

28 + 2 + 3 = …..

Now let’s try one together

Susan collects badges. She has 34 badges and is given 8 more. How many badges does she have now?

34 + 8 = …..

Now let’s try one together

Step 1: Split 8 into two numbers so that when we add one of the numbers to 34 it will bring us up to forty .

Write this out on a piece of paper now.

34 + 8 = …..

Now let’s try one together

Step 2: We’ve added the six to get to 40. Now we need to add the two.

Do this on your paper now.

34 + 8 = …..

Now let’s try one together

Answer: That means: 34 + 8 = 42

34 + 8 = …..

Review:1) We split the 8 into a 6 and a 2.

8

6 2

34 + 6 = 40

40 + 2 = 42

2) We then added the 6 to make a tidy number.

3) Then we added the remaining 2 to give us our answer

Now try these questions on your own.

1) 28 + 9 = …..

2) 37 + 5 = ….

3) 65 + 8 = ….

4) 24 + 7 = ….

5) 46 + 8 = ….

6) 53 + 9 = ….

7) 36 + 7 = ….

8) 27 + 6 = ….

9) 55 + 8 = ….

10) 39 + 4 = ….

Only click again if you have completed all the questions on the previous slide and you are

ready to see the answers.1) 37

2) 42

3) 73

4) 31

5) 54

6) 62

7) 43

8) 33

9) 63

10) 43

Need some more practise? Try Pg40 of Teacher Tools Addition and Subtraction Book Numeracy resources