1.4 Integers and Absolute Value

1.4 Integers and Absolute Value I can graph integers on a number line. I can evaluate absolute value expressions.

Integers 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

Practice Write an integer for each situation: 5 degrees below zero -5 A loss of 12 yards -12 A bank deposit of $80 +80

Graphing Integers Negative integers Positive integers When graphing integers, we use a number line. Zero is neither positive nor negative

Practice Graph the set of integers on the number line. {4,-2,3,8} {5, 2, 0, -1, -6}

Absolute Value 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

Practice |6| |0| |-5| What About… -|-9| -|13| |-14|-|2| In the order of operations, absolute value acts as parentheses

Evaluating Absolute Value Expressions 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

Comparing Numbers 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.

Practice Compare the following numbers: 0 and -4 -6 and -8 -|4| and -|-5| |-3| and |8| |-2| and |2|

Assignment Section 1.4 Worksheet

1.4 Integers and Absolute Value