1. Ratios Part III Working with Rates and Unit Rates

2. Review……..  A ratio is a comparison of numbers by division.  ORDER MATTERS  Ratios are written in the form of fractions How many ratios can you write for these shapes????? stars3 circles6 total9

3. A rate is a ratio that compares quantities in different units. A unit rate is a rate with a second term of 1. Remember, the word “unit” is used to indicate the number 1. Miles per hour, price per ounce, and price per gallon are unit rates.

4. You can drive 425 miles on a tank of gas. Your car holds 12.5 gallons for one tank. How far can you drive on one gallon of gas? 34 miles 425 miles ÷ 12.5 = _______ 12.5 gallons ÷ 12.5 1 gal Two liters of spring water cost $1.98. How much would one liter cost? $ 1.98 ÷ 2 = 2 liters ÷ 2 1 liter $.99 You are REQUIRED to write the original rate and the solving process…………. $$$$$$ qty.

5. Consumer Application A 3-roll pack of paper towels costs $2.79. A 6-roll pack of the same paper towels costs $5.46. Which is the better deal? Write the rate. $2.79 3 rolls _____ $2.79 ÷ 3 3 rolls ÷ 3 _________ Divide both terms by 3. $0.93 1 roll _____ $0.93 for 1 roll. $.93 per roll Write the rate. $5.46 6 rolls _____ $5.46 ÷ 6 6 rolls ÷ 6 _________ Divide both terms by 6. $0.91 1 roll _____ $0.91 for 1 roll. The 6-roll pack of paper towels is the better deal. Follow the rules or lose the privilege.

6. Use these unit rates to find the best price on dish detergent. Regular: price $1.20 = $.10/fl oz ($1.20÷12) volume 12 fl oz Family: : price $2.24 = $.08/fl oz ($2.24÷28) volume 28 fl oz Economy: price $3.60 = $.09 fl oz ($3.60÷40) volume 40 fl oz The Family size is the best deal. The unit price is $.08 per ounce. What processes did you use to create these unit rates? Be prepared to describe the math you used. We are dividing both terms by the 2 nd term. This will give us a 2 nd term of 1….. Please notice that the second term is an “understood” 1.

7. Unit Price The table shows prices for different packages of index cards. What size has the lowest unit price? Size Price (cards) 100 $2.70 50 $1.30 25 $.75 100 cards: Price __________ = __________ number of cards 100 card 50 cards: Price __________ = __________ number of cards 50 card 25 cards: Price __________ = __________ number of cards 25 card $2.70 $.027 $1.30$.026 $.75$.03 Best Buy 0

8. An adult’s heart beats about 2100 times every 30 minutes. A baby’s heart beats about 2600 times every 20 minutes. How many more beats does a baby’s heart beat in an hour? Find two different ways to solve this. Show your work, please.

9. What did we accomplish? We extended our working with ratios to include rates and unit rates. We started solving problems using unit rates. More to come!!!!!!