1. Interesting Integers!

2. What you will do today --
Learn rules for subtracting integers.
Practice using tiles and the number line.
Are you ready??

3. We will use algebra tiles to solve some subtraction problems
Red is positive
Yellow is negative
1 yellow + 1 red = 0

4. Let’s try a problem =

5. Subtracting Integers
To subtract integers, add its opposite!
2 – 7
2 + (-7)
Follow the add rules

6. Here are some examples
5 – (+5)
5+ (-5) = 0
5 – (+10)
5 + (-10) = -5

7. Integer Subtraction Rule
Subtracting a negative number is the same as adding a positive. Change the signs and add.
2 – (-7)
is the same as
2 + (+7)
2 + 7 = 9!

8. Here are some more examples.
12 – (-8)
12 + (+8)
= 20
-3 – (-11)
-3 + (+11)
= 8

9. 2 – (+7)= 7-2=5 4 – (-5) = 4 +5 = 9 -10 – (-6) = -21 – (+63) =
Forget the sign, find the difference, use the sign of the larger
4 – (-5) =
4 +5 = 9
-10 – (-6) =
-21 – (+63) =
= -4
Forget the sign, find the difference, use the sign of the larger
63 – 21 = 42

10. Try these
1. 8 – (-12) =
2. 22 – (-30) =
3. – 17 – (-3) =
4. –52 – 5 =

11. 8 – (-12) = = 20
2. 22 – (-30) = = 52
3. – 17 – (-3) = = -14
4. –52 – 5 = (-5) = -57

12. Homework:
page 66 #39 through #47 ALL