Checking Needed Skills p. 14 6( 9 + 1) 6(10) – ∙ ( 9 + 1) 6(10) – ∙ [ 3(5) + 1 ] ∙ 2 [ ] ∙ 2 [ 16 ] ∙ 2 32

1.3 Using Order of Operations to Evaluate Expressions Process…..process…..process

For the rest of the year, you will keep hearing three words, even in your sleep! Write SubstituteSolve

1.3 Evaluating Expressions text p. 14 We have defined variables and variable expressions. In this lesson, we will WRITE the variable expression, SUBSTITUTE the given value for each variable, and SOLVE (simplify, evaluate) the expression. Evaluate means to find a value for……… 4y – 15 y = 9 (Write) 4(9) – 15(Substitute) 36 – 15 = 21(Solve) We have defined variables and variable expressions. In this lesson, we will WRITE the variable expression, SUBSTITUTE the given value for each variable, and SOLVE (simplify, evaluate) the expression. Evaluate means to find a value for……… 4y – 15 y = 9 (Write) 4(9) – 15(Substitute) 36 – 15 = 21(Solve) 1

Individual Practice Every Stinkin’ Step!!!!!! 63 – 5x x = 7 63 – (5)(7) If you have more than one variable, substitute all values at once. 4 (t + 3) + 1 t = 8 63 – 35 = = 45 4(8 + 3) + 1 4(11) + 1 3ab + a = 2 b = 5 c = 10 3(2)(5) = 35 You will notice I combined the steps shown in the book. A wise person will enclose multiple substituted value in parentheses

Check Understanding with multiple variables 6 (g + h) g = 8 h = 7 6(8 + 7) = 6(15) =90 2xy – z x = 4 y = 3 z = 1 (2)(4)(3) = r = 13 s = = 12

2 Solving Problems with Variable Expressions Energy drinks come in cases of 24 bottles. Write a variable expression for the number of cases a store should order to get c bottles of energy drinks. I know this from the information given to me. We always have to divide by 24 to find the number of CASES we want. c__ 24 (bottles in one case) So if I want 120 bottles, how many cases do I order? 120 = ∙ 10 = 2 ∙ CasesBottles

As the owner of the store, you pay $29 for each case of drinks. To find the cost of ANY order, what would you have to do? 1 case = 1($29) 2 cases = 2($29) 3 cases = 3($29) so……. c cases = 29c The 5 cases we ordered ????? 29c = 29(5) = $ (30 – 1) ??? =

You placed an online order for some CD’s. This particular site charges $14 for each CD plus $6 for shipping. First let’s write an expression that illustrates the cost of any order. Then let’s find the cost of 4 CD’s. Finally, we will find the cost of an order with 7 CD’s. $14 for each CD + shipping = total cost n = CD’s 14n + 6 = total cost 14(4) + 6 = total cost = $ n + 6 = total cost 14(7) + 6 = total cost $98 + $6 = $104

Group work…….work, discuss, and check 1) g g = 3 2) 2ab - c a = 3 b =4 c = 9 3 The Omelet Café buys their eggs in cartons that hold 36 eggs. What expression would tell us how many cartons we need for n eggs? Evaluate the expression you wrote for a purchase of 180 eggs (3) = = 24 2(3)(4) – – 3 = 21 n 36 eggs per carton ∙ = 5 1c = 36 2c = 72 3c = 108

The One Pizza store only sells one type of pizza. The cost of the pizza is $ The delivery charge for each order is $2.00. What expression would show the cost of ANY order? What would two pizzas cost? $16 for each pizza + delivery is total cost $16 p + $2 = total cost 16(2) + 2 = cost = $34.00

Pens and Pencils..... Mr. Goldthreate found 130 pens and pencils on the floor last night. He left 25 of them in here for us, and divided the rest among the other downstairs, 6 th grade classes. Which equation would be used to find “p,” the number of pens and pencils left in the other classes? a)P = 130 – (25 x 3) b)P = (25 + 3) c)P = (130 ÷ 3) + 25 d)P = (130 – 25) ÷ 3 p = (130-25) ÷ 3 would give the solution. p = ?????? 105÷ 3 = 35 for each of the other classes.

What objectives did we accomplish??? The End What objectives did we accomplish??? The End Write SubstituteSolve