Checking Needed Skills p. 14Checking Needed Skills p. 146( 9 + 1) 6(10) 60 17 – 2 + 3 15 + 3 18 9 + 8 2 + 4∙9 + 16 + 4 29

6( 9 + 1) 6(10) 60 17 – 2 + 3 15 + 3 18 9 + 8 2 + 4∙9 + 16 + 4 29

[ 3(5) + 1 ] ∙ 2

[ 15 + 1 ] ∙ 2

[ 16 ] ∙ 2

32

1.3Using Order of Operations to

Evaluate Expressions

1.3Using Order of Operations to

Evaluate Expressions

Process…..process…..processProcess…..process…..process

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

Write Substitute Solve

1.3 Evaluating Expressionstext p. 14

1.3 Evaluating Expressionstext 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 PracticeEvery Stinkin’ Step!!!!!!

Individual PracticeEvery Stinkin’ Step!!!!!!

63 – 5x x = 763 – (5)(7)

If you have more than one variable, substitute all values at once.

4 (t + 3) + 1 t = 8

63 – 35 = 28 44 + 1 = 45

4(8 + 3) + 14(11) + 1

3ab + a = 2 b = 5 c = 102

c

3(2)(5) + 2

10

30 + 5 = 35

You will notice I combined the steps

shown in the book.

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) - 1 24 - 1 =

r = 13 s = 11

23

= 12

2

sr

2

11132

24

2Solving 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 fromthe informationgiven to me.

We always haveto divide by 24 tofind the numberof CASES we want.

c__24 (bottles in one case)

So if I want 120bottles, how manycases do I order? 120 =

2412 ∙ 10 = 2 ∙ 12

1

1

5

Cases Bottles

1 24

2 48

3 72

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)

29 5

145= $145.00

5(30 – 1) ??? = 150 - 5

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’s14n + 6 = total cost

14(4) + 6 = total cost

56 + 6 = $62.00

14n + 6 = total cost

14(7) + 6 = total cost

$98 + $6 = $104

Group work…….work, discuss, and check

1) 18 + 2g 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.

18 + 2(3) =

18 + 6 = 24 2(3)(4) – 9 3

24 – 3 = 21

n 36eggs per carton

180 36

18 ∙ 10 36

1

2

= 5

1c = 362c = 723c = 108

The One Pizza store only sells one type of pizza. The cost of the pizza is $16.00. 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

32 + 2 = $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, anddivided the rest among the other downstairs, 6th gradeclasses.

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) + 130c) P = (130 ÷ 3) + 25d) 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

Write Substitute Solve