Subtraction of Integers

Jaime CookGrand Canyon University

Tec 539

Arizona Academic Standards

Arizona Mathematics Standards Articulated by Grade Level: Grade 7

Strand 1: Number and Operations

It includes an awareness of the different types of numbers such as, whole numbers, integers, fractions, and decimals and the relationships

Concept 2: Numerical Operations Understand and apply numerical operations and their relationship to one another.

Students are expected to…

Add, Subtract, Multiple, and Divide Integers.

Recognize and convert between expressions for positive and negative rational numbers, including fractions, decimals, percents, and ratios.

Words to know…Positive number-numbers that are to the right

of zero on the number line. (Example: 5)

Negative numbers- numbers to the left of the zero on the number line. (Example -4)

Double negative- two negatives in a number sentence. (Example: 7- (-3)

Opposite numbers- two numbers that are the same distance from zero on a number line. (Example:(-8) is an opposite number from +8 (or 8), and  5 is the opposite of (-5).

Subtracting Positive and Negative Integers

Subtracting Positive Integers

5 − 8

1. Start at the positive number 5.2. Move 8 units to the left.3. End at the number -3.

Subtracting Negative Integers -4 − (-8)

1. Start at -4 on the number line.2. You would be ready to move 8 units to the left, but the second minus sign reverses your direction.3. Instead, you move 8 units to the right, ending at 4. (Hint: double negative, add the opposite)

Subtracting Positive and Negative Integers

-1 − 3

1. Start at -1 on the number line.

2. Move 3 units to the left.

3. End at -4.

(This is identical to interpreting the addition -1 + (-3) on the number line.)

Watch This!http://www.youtube.com/watch?v=Va_CiPK49vU&feature=

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Practice3 – 5 = ____

(-2) – (-3) = ____

1 - (-3) = ____

-2 – 2 = ____

(-5) - (-8) = ____

Check3 – 5 = -2

(-2) – (-3) = 0

1 - (-3) = 5

-2 – 2 = -4

(-5) - (-8) = 3