Section 2.1

Rational Numbers on the Number Line

Different types of numbers:

Natural Numbers: 1, 2, 3, 4…..

Whole Numbers: 0, 1, 2, 3, 4….

Integers: …-3, -2, -1, 0, 1, 2, 3…

Rational Numbers: numbers that can be expressed in the form a/b; where a and b are integers AND b ≠ 0.

IntegersIntegers are zero, positive and negative whole numbers

Which of the following is not an integer?

5 0 -7.25π

-2 9 305-17

-12.5 -1/2 n 0

0.5 4/2 16/4901

Creative a number line like the one below and graph the points with the following coordinates:

-8 5 / 30

17/2 11/3-5/2

Graphing Rational Numbers on the Number Line

Graph all integers less than -7

Absolute ValuePay EXTRA attention to this:

The Absolute Value of a number is the distance the number is from 0 on the number line.

For example:

Ι7Ι = 7

Ι1Ι = 1

Ι-5Ι = 5

Ι3Ι + Ι4Ι

3 + 4 = 7

I-3I + I-4I

3 + 4 = 7

6 + I-3I

6 + 3 = 9

Evaluate the follow expressions if x = -4and y = 6

1. 3 + IxI 2. IyI + IxI3. Iy + xI4. 7IxI5. 2IxIIyI 6. Ix+yI