Evaluating ExpressionsEvaluating Expressions

Real World ExamplesReal World Examples

Page 2 & 4 in Practice WorkbookPage 2 & 4 in Practice Workbook

Page 2, #22Page 2, #22

A side table has interior storage space in the A side table has interior storage space in the shape of a cube. What is the volume of shape of a cube. What is the volume of the storage space if the interior length is the storage space if the interior length is 12 inches?12 inches?

V = BhV = BhV = lwhV = lwhV = (12)(12)(12)V = (12)(12)(12)V= 1728V= 1728

Page 2, #23Page 2, #23There are 52 playing cards in a standard deck There are 52 playing cards in a standard deck

of playing cards. You are combining decks of playing cards. You are combining decks of cards so that you can play ba game with a of cards so that you can play ba game with a large number of people. The expression 52d large number of people. The expression 52d represents the number of cards in d decks. If represents the number of cards in d decks. If you combine 4 decks of cards, ow manu you combine 4 decks of cards, ow manu cards will you have all together?cards will you have all together?

52d52d52(4) = 208 cards52(4) = 208 cards

Page 2, #24Page 2, #24

An item costs c dollars and 6% sales tax is An item costs c dollars and 6% sales tax is charged. The total cost including sales tax charged. The total cost including sales tax is given by the expression 1.06c. You are is given by the expression 1.06c. You are buying a skateboard that costs $75. What buying a skateboard that costs $75. What is the cost of the skateboard including is the cost of the skateboard including sales tax?sales tax?

1.06c1.06c1.06 (75) = $79.501.06 (75) = $79.50

Page 4, #24Page 4, #24

Three weeks ago, an art supply bstore Three weeks ago, an art supply bstore started selling a paint kit for 75% of the started selling a paint kit for 75% of the original price. Now the kit is 15% off of the original price. Now the kit is 15% off of the sale price. The expression sale price. The expression

.75x – 0.15(0.75x) .75x – 0.15(0.75x) represents the current price of the paint kit represents the current price of the paint kit

where x is the kit’s original price (in where x is the kit’s original price (in dollars). Find the current price if the kit dollars). Find the current price if the kit originally cost $48originally cost $48

Page 4, #24 (continued)Page 4, #24 (continued)

.75x – 0.15(0.75x).75x – 0.15(0.75x)

.75 (48) – 0.15(0.75)(48).75 (48) – 0.15(0.75)(48) 36 – 5.436 – 5.4 30.630.6

Since this is money, we saySince this is money, we say$30.60$30.60

Page 4, #25Page 4, #25

You are decorating the perimeter of the You are decorating the perimeter of the ceiling of your living room with crown ceiling of your living room with crown molding. The expression 2x + 2y molding. The expression 2x + 2y represents the total amount of molding you represents the total amount of molding you need where x is the width of the room (in need where x is the width of the room (in feet) and y is the length of the room (in feet) and y is the length of the room (in feet). Find the total amount of wood you feet). Find the total amount of wood you need if the room is 11 feet wide and 10.5 need if the room is 11 feet wide and 10.5 feet long.feet long.

Page 4, #25 (continued)Page 4, #25 (continued)

2x + 2y2x + 2y2(11) + 2 (10.5)2(11) + 2 (10.5)22 + 2122 + 2143 inches43 inches

TranslatingTranslating

Now, let’s look at translating Now, let’s look at translating verbal phrases into expressionsverbal phrases into expressions

The difference of 9 and a The difference of 9 and a number nnumber n

9 - n9 - n

2m + 252m + 25

25 more than twice a 25 more than twice a number mnumber m

Words for OperatorsWords for Operators

We discovered that many different We discovered that many different words are used to indicate words are used to indicate

operations.operations.

AddAdd Increase sum plus total all Increase sum plus total all togethertogether

SubtractSubtract Decrease difference minus lessDecrease difference minus less

Less than (switch)Less than (switch)

Lower Lower

descenddescend

MultiplyMultiply Product Product

OF times OF times

Double or twice (x2)Double or twice (x2)

DivideDivide Quotiient share equally divide Quotiient share equally divide

Half (divide by 2)Half (divide by 2)

Brainstorm as a class !! Record all of your responses.