2-1 rational numbers & absolute value
TRANSCRIPT
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