2. 8+5 =

3. 9+8 =

4. I count up to 8 in
my head then count
on 9, 10, 11, 12, 13

5. I get 8 counters
and 5 more
counters then
count them all.

6. 8 + 2 = 10 so 10 + 3 is 13
9 + 1 is 10 so 10 + 7 is 17

7. I count on from
the biggest
number.
So I go 9… 10, 11,
12, 13, 14, 15, 16,
17, 18

8. 8 + 8 is 16 then
add 1 OR
9 + 9 is 18 then
takeaway 1

9. There are 36 people on the
bus. 9 more people get on
the bus.
How many people are there
altogether on the bus?
What strategies would you use to
solve this problem?

11. 36+9
=

12. If you add 4 onto
36 you get 40 then
you add on the
other 5 to get 45
people on the bus

13. I counted on
from 36 using my
fingers and got
to 45.

14. Add on 10 then
takeaway 1.
When you add on 10 you
get 46 then you need to
takeaway 1 to get 45.

15. I know that 6
plus 9 is 15,
so 30 + 15 is
45.

16. I know 6 + 6 is 12
so 36 + 6 = 42.
Then add on the 3
more to get 45.

18. Te Kaha has 47 marbles. He
plays Stacey and loses 8
marbles to Stacey.
How many marbles is Te
Kaha left with?
What strategies would you use to
solve this problem?

19. I used balancing.
+2 47 – 8 = I compensated:
+2
49 – 10 = 39 47 – 10 = 37
37 plus 2 = 39
47 – 8 =
If I split 8 into 7
and 1, so I can do
47 – 7, which equals
40, then I only have
I used an open number line! to take away one
-1 -7 more, which equals
+ 39!
39 240 47
0

20. Number Strategies
There are 53 people on the bus.
29 people get off.
How many people are left on the
bus?
What strategies would you use
to solve this problem?

21. I used place value
53 – 20 = 33. Minus another I used tidy
9. Split the 9 into 3 and 6. numbers:
33 - 3 = 30 so 30 – 6 = 24 53 – 30 = 23
23 plus 1 = 24
I used an open number line!
53 – 29 =
+20 +3
I think of
+1
+
53
29 2
30 50 53 -29
0 3 – 9 I can’t do so I
borrow a ten.
13 – 9 = 4.
I used balancing. 4 tens – 2 tens =
+1 53 – 29 +1
= 20.
54 – 30 = 24 It’s 24.

22. Number Strategies
There are 47 children in the
hall. 28 more children arrive.
How many children are in the
school hall now?
What strategies would you use to solve
this problem?

23. Four rows of ten is 40 and two
rows of ten is 20, so 40 + 20 = I used tidy
60 with 7 and 8 left! numbers:
Double 7 = 14 plus 1 = 15 50 + 28 = 78
so there are 75 children. 78 - 3 = 75.
I use an open number line!
47 + 28 =
+3 I think of
+20 +5 47
47 +28
75
7 plus 8 is 15, so
that’s 5 and carry
one. 4 plus 2 is 6
I know that 50 plus 30 is 80 plus one more ten
and 3 plus 2 is 5, is 7. so the
so 80 - 5 is 75. answer is 75.

24. Number Strategies
8+5=
9+8=

25. Make sense of these strategies
I count up to 8 in my head I get 8 counters
then count on 9, 10, 11, 12, and 5 more
13 counters then
count them all.
8+5=
8 + 2 = 10 so 10 + 3 is 13 9+8= I count on from
9 + 1 is 10 so 10 + 7 is 17 the biggest
number.
So I go 9… 10, 11,
12, 13, 14, 15, 16,
17, 18
8 + 8 is 16 then add 1 OR
9 + 9 is 18 then takeaway 1

26. Number Strategies
I have $387 in my savings account.
I decide to buy a small TV for my
bedroom and it costs $193.
How much money do I have left?
What strategies would you use to solve
this problem?

27. I rounded up to 390 and
takeaway 190 to get 200. I used my doubles.
then I need to take away Double 190 is 380.
the 3 I added on plus the So double 193 is
other 3 so its 194. 386 plus 1 more to
get 194.
“I use an open number line!”
387 - 193 =
+100 +87
“I think of
+7
+
387
193 2
200 300 387 -193
0 7- 3 is 4. 8 – 9 I
can’t do so I borrow
a hundred.
I use balancing. 180 – 90 = 90.
-3 387 – 193 =
-3 200 – 100 is 100.
384 – 190 = 194 It’s 194.

28. Number Strategies
I have a 6.3m length of fabric.
I used 3.75m to make a coat.
How much fabric have I got
left?
What strategies would you use to solve
this problem?

29. 6.3 – 2.3 = 4
4 – 0.25 = 3.75 What visual
so 2.3 + 0.25 = supports could
you use to
2.55m support these
strategies?
“I used an open number line!”
+0.25 +2 +0.3
+
3.75 2 4 6 6.3 What knowledge do
0
students require to
solve problems at
this level?
6
6.3 – 3.75 =

30. Addition and Subtraction
Strategies
Counting Counting all
Counting on/back
___________________________
Part- Using one fact to derive another
whole Near-doubles
Making tens
Using fives
Known multiple facts
Partitioning
Standard place value partitioning
Rounding & compensating
Through the tens
Reversibility
Equal additions
Commutative
Averaging
Equivalency