Todays Objective To be able to use ratios

Today’s Objective • To be able to use ratios and relate quantities in the same units.

Suppose…. . • You had two U. S. coins that total 55 cents. One of the coins is not a nickel, what are the two coins?

Suppose…. . • That you were riding in the back seat of a car that was traveling on I-10 and you wanted to determine the speed of the car without looking at the speedometer. Is this possible?

Yes… Speed is determined by How many miles traveled in an hour • Step 1. . Find out, in seconds, how long it takes to travel between any two mile markers (distance is 1 mile). • Step 2. . Determine how many seconds in an hour. • 1 hour = • 1 minute =

Convert 1 hour to seconds • 1 hour = 60 minutes • 1 minute = 60 seconds • So 1 hour =60 minutes x 60 seconds • 1 hour =3600 seconds

Determine mph (speed) • 1 miles • 3600 sec = 65 sec hour • 3600 miles = 55. 3 miles hour 65 hour

Using Rates • Miles per gallon = mpg • If it takes 11 gallons to drive 250 miles, What is the mpg? • 250 miles / 11 gallons = • 22. 7 miles / gallon

Using Rates • Dollar / hour = hour wage • If you work 4 hours and get paid $20. 00, What is your hourly wage? • 20 dollars / 4 hour = • 5 dollars / hour

Using Ratios • Hair grows at a rate of 5 inches per year. How much would your hair grow in 6 months? • 5 inches • 1 year = 1 year 2

Classwork • Do worksheet 2. 8 • homework • page 110 (1 -19)