2-1 Rational Numbers on the Number Line

Bellwork

• Identify the Property

1. 6 + 1 = 1 + 62. 9 + 0 = 93. 4(6 + 2) = 4(6) + 4(2)4. 5 ∙ 1 = 55. 3 ∙ (4 ∙ 5) = (3 ∙ 4) ∙ 5

Objective

• Students will graph numbers on a number line and find absolute value

Vocabulary

• Negative Number – A number less than zero

• Integers – the set of numbers that includes zero and all positive and negative non-decimal, non-fraction numbers.

• Absolute Value – The distance a number is from zero on the number line.

• Note: Absolute value can never be negative!

5 = 5= 8-8

When we want to find the absolute value of a number,We write two vertical lines around the number.

5 is 5 spaces away from 0.

How far is it from zero?

Graphing on a Number line• Integers can be graphed on a number line.

To do so…simply locate the number on the number line and put a dot.

• The dot represents the coordinate of that number on the number line

Evaluating Expressions

• Treat the Absolute Value sticks like parantheses, and do any operations in them first.

Example

|5| + | -6|

5 + 6 = 11

Evaluating Expressions

• If the expression has an absolute variable use the substitution method

1. Write the expression2. Substitute3. Do the math

Example8 + |n| where n = -128 + | -12|8 + 12 = 20