What is a ratio? ThinkWriteShare

A ratio is…. n A comparison of two numbers. n It can be written several ways n As a fraction n Using a colon n Using the word to

Let’s find the ratio of girls to boys in the class n Write it three ways on your dry board n What is the ratio of teachers to students in the class? n Write it three ways on your dry board!

Remember to always simplify- yes- even a ratio can be simplified!! n Express each ratio as a fraction in simplest form: n 4 goals to 10 attempts n 2/5

Express each ratio as a fraction in simplest form: n 15 dimes out of 24 coins n 15/24 n 5/8

Express each ratio as a fraction in simplest form: n 4 weeks to plan 2 events n 4/2 n 2/1

What if… n You are comparing units? n What is a unit? n Think n Write n Share

n 3 feet to 16 inches n We must first convert our larger units into smaller units. n How could we change feet into inches? n Think, Write, share

n Multiply 3 feet by 12, because there are 12 inches in 1 foot. 3 feet (12) = 36 inches 16 inches 16 inches Don’t forget to simplify! 36/16 = 9/4

Try some on your dry board: n 11 gallons to 11 quarts n Change gallons to quarts. n How many quarts are in a gallon? n 1 gallon = 4 quarts 11gallons (4 ) =44 quarts 11 quarts 11 quarts 44/11 = 4/1

Try: n 18 miles to 18 yards n How many yards are in a mile? n 1760 yards = 1 mile 18 miles(1760) = yards 18 yards 18 yards 31680/18= 1760/1

Try: n 10 inches to 3 feet n 12 inches = 1 foot 10 inches = 10 inches 3 feet (12) 36 inches 10/36= 5/18

What is a rate? n Think n Write n Share

A rate…. n A ratio of two measurements n They have different kinds of units n Examples: n Miles/gallon n Dollars/pound

Can you think of any more examples of rate? n Write them on your dry board. n Share with your team n Share with the class

What is a unit rate? n Think n Write n Share

A unit rate is when a rate is simplified so the denominator is equal to one. n 18 dollars/ 20 CDS n How much is 1 CD? n To find the unit rate divide both the numerator and the denominator by the denominator!

18 dollars ÷ 20 = CDS ÷ 20 = 1 Each CD costs 0.90 cents each!

Try some on your dry board: n Find the unit rate for each rate: n $3 dollars for 6 cans of tuns. n To find the unit rate I want to find out how much one can costs. n Divide the numerator and denominator by 6. $3 ÷ 6 = can of tuna is 0.50 cents 6 ÷ ÷ 6 1

Try: Find the unit rate n 140 miles on 6 gallons 140 miles ÷ 6 = miles 6 gallons ÷6 1 gallons 6 gallons ÷6 1 gallons 23.3 miles/gal

Try: Find the unit rate: n 25 feet in 3.2 hours 25 feet ÷ 3.2 = feet 3.2 hours ÷ hour feet/hr

You will get WS 300 n Put your name on the top n You will solve a problem n When you hear the buzzer, rotate papers n Simultaneous Roundtable

Homework: n WS 301 all