1. Lesson 1.3 Write Expressions Essential Question: How do you write an expression to represent a real- world situation?

2. Before we start… You want to invite some friends to a football game. You know tickets cost $4 each. How would you determine how much it cost for you and your friends to get in the game? –Tell your partner.

3. What is an algebraic expression? We can write algebraic expressions from words. Numbers Operations Variables

4. How can we translate from words to expressions? To translate from words to expressions we want to look for words that indicate mathematical operations.

5. Translating Verbal Phrases Order is IMPORTANT when writing subtraction and division expressions. OperationKey WordsVerbal PhraseExpression AdditionSum, plus, total, more than, increased by The sum of 2 and a number n SubtractionDifference, less than, minus, decreased by The difference of a number n and 6 MultiplicationTimes, product, multiplied b, of DivisionQuotient, divided by, divided into The quotient of a number k and 2

6. Translate these verbal phrases into expressions

10. A piece of ribbon l feet long is cut from a ribbon 8 feet long. Write an expression for the length (in feet) of the remaining piece.

11. The length of a building is 20 feet more than its width w. Write an expression for the length of the building.

13. How do you write an expression to represent a real-world situation? Translate the verbal phrase in the problem into operations and variables. Create a verbal model. Translate the verbal model into an expression.

14. What is a verbal model? Describes a real-world situation using words as labels and math symbols to relate the words. Replace the words with numbers and variables.

15. You work with 5 other people at an ice cream stand. All the workers put their tips into a jar and share the amount in the jar equally at the end of the day. Write an expression for each person’s share (in dollars) of the tips.

16. You and 4 friends meet to have dinner at a restaurant. Everyone decides to order the nightly special. Write an expression for the total cost of the meals.

17. The speed limit on some parts of Route 220 is 55 mph. Is this a unit rate?

18. What is… A rate? A fraction that compares two quantities measured in different units. A unit rate? A rate in which the denominator of the fraction is 1 unit. Walking 5 miles in 90 minutes. Earning $7.25 per hour.

19. A car travels 220 miles in 4 hours. Find the unit rate.

20. A 16 ounce box of cereal costs $2.99. Find the unit rate to the nearest cent.

21. The New York Yankees scored 12 runs in 9 innings. How many runs per inning did they score?

22. Find the unit rate. 4.5 pints in 3 servings. $136 in 20 shares.

23. To solve a problem… We may need to write an expression or find a unit rate.

24. Photographs You can print color photos from your digital camera at a photo printing kiosk. The cost is $0.25 per photo. Write an expression for the total cost if you print p photos. How much does it cost you to print 12 photos?

25. Candle Making You are making candles for your friends. A mold for the candles costs $22.50 and wax to make one candle costs $5. Write an algebraic expression for the total cost of making x candles. You make 8 candles. Find the total cost.

26. Cell Phones Your basic monthly charge for cell phone service is $30, which includes 300 free minutes. You pay a fee for each extra minute you use. One month you paid $3.75 for 15 extra minutes. Find your total bill if you use 22 extra minutes.

27. Car Trip You are getting ready to make a 640-mile car trip. In general, your car can drive 160 miles on 5 gallons of gasoline. How many gallons of gasoline will you use for the trip? You started out with 4 gallons of gasoline in your car and gasoline is $2.29 per gallon. How much money will you spend on gasoline on the trip?

28. A 48 ounce container of juice costs $2.64. A 64 ounce container of the same juice costs $3.84. a) Find the cost per ounce of each container. b) Which size container costs less per ounce? c) You want to buy 192 ounces of juice. How much do you save using the container size from your answer to part (b)?

29. How do you write an expression to represent a real-world situation?

30. Ticket Out the Door Write an expression for the situation on a piece of paper (put your name on it) and place it in the box on your way out… The number of miles left in a 425-mile trip after m miles have been traveled.