I can graph integers on a number line.
I can evaluate absolute value expressions.
1.4 Integers and Absolute Value
• A whole number that can be positive or negative (or zero)• Whole numbers and their
opposites• {… -4,-3,-2,-1,0,1,2,3,4,…}• NO decimals/fractions
Integers
Write an integer for each situation:• 5 degrees below zero• -5
• A loss of 12 yards• -12
• A bank deposit of $80• +80
Practice
When graphing integers, we use a number line.
Graphing Integers
Negative integers Positive integers
Zero is neither positive nor negative
Graph the set of integers on the number line.• {4,-2,3,8}
• {5, 2, 0, -1, -6}
Practice
The distance between a number and zero on the number line.• Absolute value is illustrated by
placing a number or expression inside vertical bars.
• Ex: |3| = • 3
• |-3| =• 3
Absolute Value
• |6|• |0|• |-5|What About…• -|-9|• -|13|• |-14|-|2|• In the order of operations,
absolute value acts as parentheses
Practice
Same steps to evaluate an algebraic expression.Try it!• |x| + 7 if x = -13 |-13| + 7 13 + 7 20• |a|●|b| - 12 if a = -5 and b = 8• 28
Evaluating Absolute Value Expressions
Numbers can be compared using the following symbols:• < means “less than”• Ex: 2<7 “2 is less than 7”
• = means “equal”• Ex: -3=-3 “-3 is equal to -3”
• > means “greater than”• Ex: 5>-1 “5 is greater than -1”
Comparing Numbers
How can you tell one number is less than another?• Graph them on a number line.• Compare -2 and -4
Graph the numbers to see where they lie
-2 > -4 since -4 is lower on the number line.
Comparing Numbers
Compare the following numbers:
• 0 and -4• -6 and -8• -|4| and -|-5|• |-3| and |8|• |-2| and |2|
Practice
Section 1.4 Worksheet
Assignment