Transcript Adding in parts

Adding in Parts
I am learning to add by splitting numbers into parts.
Example : 8 can be split into
or 3 and 5
1 and 7
or 2 and 6
or 4 and 4
SAMPLE PROBLEM
Andrew has picked 28 cherries. He picks 5 more cherries.
How many cherries has he picked in total?
Number of
cherries he
had already
picked.
Number of extra
cherries he has
just picked.
28 + 5 = …..
Total number of
cherries he has.
SAMPLE PROBLEM
28 + 5 = …..
Step 1: I want to get 28 to a tidy number. The
closest tidy number is 30.
Step 2: Now I think 28 plus what would equal
30.
28 + 2 = 30
SAMPLE PROBLEM
28 + 5 = …..
Step 3: I took the 2 from the five which
means I have three left over.
5
2+3
28 + 2 = 30
30 + 3 = 33
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.
SAMPLE PROBLEM
28 + 5 = …..
Answer: 28 + 5 = 33
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
34 + 8 = …..
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.
Now let’s try one together
34 + 8 = …..
Step 2: We’ve added the six to get to 40. Now
we need to add the two.
Do this on your paper now.
Now let’s try one together
34 + 8 = …..
Answer: That means: 34 + 8 = 42
Review:
1) We split the 8 into a 6 and a 2.
8
6
2) We then added the 6 to make a tidy number.
2
34 + 6 = 40
3) Then we added the remaining 2 to give us our answer
40 + 2 = 42
Now try these questions on your own.
1) 28 + 9 = …..
6) 53 + 9 = ….
2) 37 + 5 = ….
7) 36 + 7 = ….
3) 65 + 8 = ….
8) 27 + 6 = ….
4) 24 + 7 = ….
9) 55 + 8 = ….
5) 46 + 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
6) 62
2) 42
7) 43
3) 73
8) 33
4) 31
9) 63
5) 54
10) 43
Need some more practise? Try Pg40 of Teacher Tools Addition and
Subtraction Book Numeracy resources