Interesting Integers!Let’s subtract.

What You Will Learn Rules for subtracting Method for subtracting

Are you ready??

We will use algebra tiles to solve some subtraction problems

Remember zero pairs – 1 set of opposite colors will be a zero pair

Red is positive

Yellow is negative

1 yellow + 1 red = 0

Let’s try a problem

-2 - 4 =

This is our zero pair bank

Problem: 4 - 2

-2 - 4 =

Remove 4 red (positive)

Problem: 5 - -2

Problem: -3 - -4 =

Subtracting Integers

To subtract integers, add its opposite!2 – 7

2 + (-7)

Follow the add rules

Here are some examples

5 – (+5)

5+ (-5) = 0

5 – (+10)

5 + (-10) = -5

Integer Subtraction RuleSubtracting 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!

Here are some more examples.

12 – (-8)

12 + (+8)

12 + 8 = 20

-3 – (-11)

-3 + (+11)

-3 + 11 = 8

2 – (+7)=

4 – (-5) =

-10 – (-6) =

-21 – (+63) =

7-2=5

4 +5 = 9-10 + 6 = -4

63 – 21 = 42

Forget the sign, find the difference, use the sign of the larger

Forget the sign, find the difference, use the sign of the larger

Try these

1. 8 – (-12) =

2. 22 – (-30) =

3. – 17 – (-3) =

4. –52 – 5 =

8 – (-12) = 8 + 12 = 20

2. 22 – (-30) = 22 + 30 = 52

3. – 17 – (-3) = -17 + 3 = -14

4. –52 – 5 = -52 + (-5) = -57

Homework – page 268/269

16 through 28 all

FormativeOrder least to greatest

-10 0 8 -14 22 -1.2 1.3

Solve

-15 + 8 =

-4 - -4 =

5 + -3 =

-4 - +6 =

HomeworkBased on formative results-from textbookOrdering and comparing – pg 24 #1, #2Adding pg 27 #5, #6, #7, #8Subtracting pg 28 #1 #2 #3 #4