2.1 Integers and absolute value Objective: Students will be able to tell me what the absolute value of a number is. They will also be able to plot a point on a number line in relation to a given number. Finally, students will show that they understand how to solve a variable expression with an absolute value problem involved.

Definitions Integers: positive/negative whole numbers. Negative integers: integers less than zero. Larger neg. #, smaller amount Positive integers: integers more than zero. Larger pos. #, larger amount Zero neither positive or negative. From the list which ones are integers. 3/4, 5, -26, .54

Which Numbers below are integers? 5, 4.5, 6/7, 23, -8 4, 2/3, 8.9, -32, 534, 0.3 Write Integers. Loss of 5yds 22 below zero Increase of 45% Deposit of $60

Write integer for situation? Grade lowered by 8pts The temperature fell 4 degrees Gained $4000 in stock market Loss of 10yds 23 above zero Increase of 45%

Definitions Coordinate: point on line goes with number. Order using number line 2, -5, 8, 10, 9, -8, -1 -10 -5 0 5 10 15

Student Example Order by using number line. 8, 5, -11, 0, -3 -15 -10 -5 0 5 10 Order the following numbers from least to greatest. -14, 11, -12, 7, -9 -15 -10 -5 0 5 10

Absolute Values Absolute value: distance from zero on a number line. Uses l n l symbols Ex: l 8 l Final answer positive! Ex: l -9 l = 9 Find absolute value. l 98 l = l -6 l = l -11 l =

Student Examples state the absolute values l 100 l - l 102 l l -12 l l 78 l - l 173 l l 214 l l -131 l l 65 l

variable expressions Examples: Solve when x = -5 Will do these all year long!!!! To solve, substitute number for each variable. Examples: Solve when x = -5 -x 12 – l x l - l x l

Student Examples Solve when x = 6 l x l + 9 5 l x l 36 / l x l

Wrap up Questions/Comments Ic: Hw: