Lesson 2-3 Pages 70-74

Subtracting Integers

What you will learn!1. How to subtract integers.

2. How to evaluate expressions containing variables.

What you really need to know!

Subtracting Integers:To subtract an integer, add its additive inverse.

In plain English:Add the opposite of the number!

What you really need to know!

When you read the problem, say “and opposite of” for the minus sign!

Example 1:

Find 9 - 14-5

Think: 9 + (-14)

Example 2:

Find -10 - 8-18

Think: -10 + (-8)

Example 3:

Find 15 – (-4)19

Think: 15 + 4

Example 4:

Find -10 – (-7)-3

Think: -10 + 7

Example 5: What is the range for Wyoming?

StateState Lowest Temp Lowest Temp °F°F

Highest Temp Highest Temp °F°F

UtahUtah -69-69 117117

VermontVermont -50-50 105105

VirginiaVirginia -30-30 110110

WashingtonWashington -48-48 118118

West VirginiaWest Virginia -37-37 112112

WisconsinWisconsin -54-54 114114

WyomingWyoming -66-66 114114

114 + 66 = 180°F°F114 – (-66)

Example 6:

Evaluate:

m – (-2) if m = 4

6

Example 7:

Evaluate:

x - y if x = -14 and y = -2.

-12

Example 8:

Evaluate:

p + q – r

if p = -11, q = 6, and r = -12.

7

Page 72

Guided Practice

#’s 3-13

Pages 70-72 with someone at home

and study examples!

Read:

Homework: Pages 73-74

#’s 14-52 even

#’s 57-74

Lesson Check 2-3

Page

727

Lesson 2-3

Lesson Check 2-3

Prepare for Mid-Test!

Pages 90-91

#’s 8-29Odd Answers in Back of Book!