Objective: Graph integers on a number line and find absolute value

Objective: Graph integers on a number line and find absolute value.

5 – 1 = 45 – 2 = 35 – 3 = 25 – 4 = 15 – 5 = 05 – 6 = ?

5 – 1 = 45 – 2 = 35 – 3 = 25 – 4 = 15 – 5 = 05 – 6 = -1

This is an example of a negative number. A negative number is less than zero.

Numbers to the left of zeroare less than zero.

Numbers to the left of zeroare less than zero.

Numbers to the right of zero are more than zero.

Numbers to the left of zeroare less than zero.

Numbers to the right of zero are more than zero.

The numbers –1, -2, -3,… are called negative integers. The number negative 3 is written –3.

Numbers to the left of zeroare less than zero.

Numbers to the right of zero are more than zero.

The numbers –1, -2, -3,… are called negative integers. The number negative 3 is written –3.

The numbers 1, 2, 3, … are called positive integers. The number positive 4 is written +4 or 4.

Numbers to the left of zeroare less than zero.

Numbers to the right of zero are more than zero.

The numbers –1, -2, -3,… are called negative integers. The number negative 3 is written –3.

The numbers 1, 2, 3, … are called positive integers. The number positive 4 is written +4 or 4.

Zero is neither negative nor positive.

Example 2a: Name the coordinates of D, E, and B

A E C B D

-6 -5 -4 -3 -2 -1 0 1 62 3 4 5

-6 -5 -4 -3 -2 -1 0 1 62 3 4 5

Absolute Value

In words: The absolute value of a number is the distance the number is from the zero point on the number line.

In symbols: |4| = 4 and |-4| = 4

a. |9| + |-9|

a. |9| + |-9| |9| + |-9| = 9 + 9

a. |9| + |-9|| |9| + |-9| = 9 + 9

= 18

a. |9| + |-9|| |9| + |-9| = 9 + 9

= 18

b. |13| - |-2|

a. |9| + |-9|| |9| + |-9| = 9 + 9

= 18

b. |13| - |-2||13| - |-2| = 13 – 2

a. |9| + |-9|| |9| + |-9| = 9 + 9

= 18

b. |13| - |-2||13| - |-2| = 13 – 2

= 11

|x| - 7 = |-13| - 7

|x| - 7 = |-13| - 7= 13 – 7

|x| - 7 = |-13| - 7= 13 – 7= 6