# Understanding addition and subtraction with the Integer Work Mat

```-20
-15
-10
-5
0
5
10
Integer work mat
15
20
How to use the “Integer work mat”
• Each blue counter is worth +1
• Each red counter is worth -1 (in other words ‘the opposite of 1’)
• If the mathematical operation is addition, this means putting
something down onto the mat
• If the mathematical operation is subtraction, this means removing
something from the mat
positive counters
down onto the mat…
One negative counter
3 + −1
positive counters
down onto the mat…
Two negative counters
3 + −2
positive counters
down onto the mat…
Five negative counters
3 + −5
negative counters
down onto the mat…
Two negative counters
−3 + −2
negative counters
down onto the mat…
Two positive counters
−3 + 2
negative counters
down onto the mat…
Five positive counters
−3 + 5
1. Which direction do you move on the number line
2. Which direction do you move on the number line
1) 2 + 7 =
2) 2 + −7 =
3) −2 + 7 =
4) −2 + −7 =
5) −4 + 2 =
6) −4 + −2 =
7) −6 + −1 =
8) 5 + −11 =
Now, let’s look at ‘subtraction’…
What does it mean to ‘subtract’ something?
Subtract from this by
removing from the mat…
positive counters
One positive counter
3−1
Subtract from this by
removing from the mat…
positive counters
Five positive counters
3−5
Subtract from this by
removing from the mat…
positive counters
Five negative counters
3 − −5
Subtract from this by
removing from the mat…
positive counters
One negative counter
3 − −1
Subtract from this by
removing from the mat…
negative counters
One negative counter
−3 − −1
Subtract from this by
removing from the mat…
negative counters
One positive counter
−3 − 1
1. Which direction do you move on the number line
when subtracting a positive integer?
2. Which direction do you move on the number line
when subtracting a negative integer?
Practice these subtraction situations:
1) 2 − 7 =
2) 2 − −7 =
3) −2 − 7 =
4) −2 − −7 =
5) 6 − 2 =
6) 6 − 10 =
7) −7 − −1 =
8) −4 − −11 =
```