What is a ratio?What is a ratio?

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A ratio is….A ratio is….

A comparison of two numbers.A comparison of two numbers.

It can be written several waysIt can be written several ways

As a fractionAs a fraction Using a colonUsing a colon Using the word toUsing the word to

Let’s find the ratio of Let’s find the ratio of girls to boys in the classgirls to boys in the class

Write it three ways on your dry Write it three ways on your dry boardboard

What is the ratio of teachers to What is the ratio of teachers to students in the class?students in the class?

Write it three ways on your dry Write it three ways on your dry board!board!

Remember to always Remember to always simplify- yes- even a ratio simplify- yes- even a ratio can be simplified!!can be simplified!!

Express each ratio as a fraction in Express each ratio as a fraction in simplest form:simplest form:

4 goals to 10 attempts4 goals to 10 attempts 2/52/5

Express each ratio as a Express each ratio as a fraction in simplest form:fraction in simplest form:

15 dimes out of 24 coins15 dimes out of 24 coins 15/2415/24

5/85/8

Express each ratio as a Express each ratio as a fraction in simplest form:fraction in simplest form:

4 weeks to plan 2 events4 weeks to plan 2 events 4/24/2 2/12/1

What if…What if…

You are comparing units?You are comparing units?

What is a unit?What is a unit?

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3 feet to 16 inches3 feet to 16 inches We must first convert our larger We must first convert our larger

units into smaller units.units into smaller units.

How could we change feet into How could we change feet into inches?inches?

Think, Write, shareThink, Write, share

Multiply 3 feet by 12, because Multiply 3 feet by 12, because there are 12 inches in 1 foot.there are 12 inches in 1 foot.

3 feet (12) 3 feet (12) = = 36 inches36 inches16 inches 16 inches16 inches 16 inches

Don’t forget to simplify!Don’t forget to simplify!36/16 = 9/436/16 = 9/4

Try some on your dry Try some on your dry board:board:

11 gallons to 11 quarts11 gallons to 11 quarts Change gallons to quarts.Change gallons to quarts. How many quarts are in a gallon?How many quarts are in a gallon? 1 gallon = 4 quarts1 gallon = 4 quarts

11gallons (4 ) 11gallons (4 ) ==44 quarts44 quarts

11 quarts 11 quarts11 quarts 11 quarts

44/11 = 4/144/11 = 4/1

Try: Try:

18 miles to 18 yards18 miles to 18 yards How many yards are in a mile?How many yards are in a mile? 1760 yards = 1 mile1760 yards = 1 mile

18 miles(1760)18 miles(1760) = = 31680 yards31680 yards

18 yards 18 yards18 yards 18 yards

31680/18= 1760/131680/18= 1760/1

Try:Try:

10 inches to 3 feet10 inches to 3 feet 12 inches = 1 foot12 inches = 1 foot

10 inches10 inches = = 10 inches10 inches

3 feet (12) 36 inches3 feet (12) 36 inches

10/36= 5/1810/36= 5/18

Ratios…..Ratios…..

Pass out WS 375Pass out WS 375 Students will complete numbers 1-Students will complete numbers 1-

12 on own12 on own Pass out talking slipsPass out talking slips Students will pass out to groupStudents will pass out to group

Talking slipsTalking slips

The number on your talking slip is the The number on your talking slip is the number of the problem you will be number of the problem you will be explaining to your team.explaining to your team.

You do not have to go in orderYou do not have to go in order Who ever places their talking slip in the Who ever places their talking slip in the

center of the table is the ONLY PERSON center of the table is the ONLY PERSON SHARINGSHARING

Others may agree or disagree with your Others may agree or disagree with your answer.answer.

When all questions have been answered When all questions have been answered place your slips back in the baggy!place your slips back in the baggy!

What is a rate?What is a rate?

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A rate….A rate….

A ratio of two measurementsA ratio of two measurements They have different kinds of unitsThey have different kinds of units

Examples:Examples: Miles/gallonMiles/gallon Dollars/poundDollars/pound

Can you think of any Can you think of any more examples of rate?more examples of rate?

Write them on your dry board.Write them on your dry board.

Share with your teamShare with your team

Share with the classShare with the class

What is a unit rate?What is a unit rate?

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A unit rate is when a rate A unit rate is when a rate is simplified so the is simplified so the denominator is equal to denominator is equal to one.one.

18 dollars/ 20 CDS18 dollars/ 20 CDS

How much is 1 CD?How much is 1 CD?

To find the unit rate divide both the To find the unit rate divide both the numerator and the denominator by the numerator and the denominator by the denominator!denominator!

18 dollars 18 dollars ÷ 20 = ÷ 20 = 0.90.9

20 CDS 20 CDS ÷ 20 = 1÷ 20 = 1

Each CD costs 0.90 cents each!Each CD costs 0.90 cents each!

Try some on your dry Try some on your dry board:board:

Find the unit rate for each rate:Find the unit rate for each rate: $3 dollars for 6 cans of tuna.$3 dollars for 6 cans of tuna. To find the unit rate I want to find out To find the unit rate I want to find out

how much one can costs.how much one can costs. Divide the numerator and denominator Divide the numerator and denominator

by 6.by 6.

$3 $3 ÷ 6 = ÷ 6 = 0.5 0.5 1 can of tuna is 0.50 cents1 can of tuna is 0.50 cents

6 6 ÷ 6 1÷ 6 1

Try: Find the unit rateTry: Find the unit rate

140 miles on 6 gallons140 miles on 6 gallons

140 miles 140 miles ÷ 6÷ 6 = = 23.33 miles23.33 miles

6 gallons 6 gallons ÷6 1 gallons÷6 1 gallons

23.3 miles/gal23.3 miles/gal

Try: Find the unit rate:Try: Find the unit rate:

25 feet in 3.2 hours25 feet in 3.2 hours

25 feet25 feet ÷ 3.2 = ÷ 3.2 = 7.8125 feet7.8125 feet

3.2 hours 3.2 hours ÷ 3.2 1 hour÷ 3.2 1 hour

7.8125feet/hr7.8125feet/hr

You will get a WSYou will get a WS

Put your name on the topPut your name on the top You will solve a problemYou will solve a problem When you hear the buzzer, rotate When you hear the buzzer, rotate

paperspapers Simultaneous RoundtableSimultaneous Roundtable