1. Warm-up: 1.Solve: 3x – 4 – 5x < 10 2.Simplify: A) -3 (x – 5) B)2 (3x – 4) 18 December 15, 2010 HW: pg. 295 #21-30 Objective: SWBAT use unit rates to solve real world problems.

2. Unit Rates

3. Definitions *Write this down! Rate – ratio that compares 2 quantities measured in different units UNIT rate – rate for 1 unit (denominator of 1) What are some RATES in the real world?

4. Driving miles per hour Typing words per minute Cost per bottle Cost per ounce Heartbeats per minute Reading pages per hour Miles per gallon

5. Scenario 1: Ms. Han’s gas mileage HIGHWAY (road trip to Philly and Virginia) I drove 386.8 miles and pumped 10.694 gallons. How many miles per gallon did I get? 386.8 miles= miles 10.694 gallons1 gallon 36.17 36.17 miles per gallon

6. CITY (back and forth to work) I drove 300.12 miles and pumped 10.612 gallons. How many miles per gallon did I get? 300.12 miles= miles 10.612 gallons1 gallon 28.28 28.28 miles per gallon Scenario 1: Ms. Han’s gas mileage

7. Scenario 2: Road trip miles per hour On my road trip to Philly, it took me 2 hours to drive 120 miles to get there. How fast did I drive? 120 miles= miles 2 hours1 hour 60 60 mph

8. On my way home, I drove the same 120 miles but in 1 hour and 45 minutes. How fast did I drive? 120 miles= miles 1.75 hours1 hour 68.57 68.57 mph Scenario 2: Road trip miles per hour

9. Scenario #3: Grocery shopping Sometimes sale prices are deceiving. You have to check the UNIT PRICE! (the little orange sticker) You can use unit rates to figure out the better buy. Divide: COST ÷ UNIT (to get the price per unit) Ex. $12 for 6 hamburgers – how much was 1 hamburger? $12 ÷ 6 burgers = $2 per burger

10. Which is the better buy? 2 liters of milk at $3.80 1.5 liters of milk at $2.70 10 pencils for $4.00 at Staples 6 pencils for $2.70 at Office Depot Kellogg’s Fruit Loops 12.2 oz box for $4.58 Giant Brand Fruit Loops 28 oz box for $4.49

11. Coffee – which is the best buy? Starbucks: 14 oz for $11.19 Dunkin Donuts: 26 oz for $7.99 Don Francisco: 12 oz for $6.25 Folgers: 3.95 oz for $5.79

12. Your turn! Worksheet – compare Giant versus Sam’s Club