Interesting Integers! Let’s subtract.. What You Will Learn Rules for subtracting Method for...

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