Dec.3

Today:

Up Coming EventsCut the Units...Not the Rates.5

Warm-Up/Review for TestClass Work: Converting Rates &

Measurement

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Dates to Remember

WashClothes

cut theGrass

Warm-Up

1. Is the following a proportion? Why or

why not:

18/3 = 96/24 2. Solve: 3 + y = -y 4 6

3. Students at MHS go to school 180 out of the 365 days in a non leap year. What percent of the year is this?

4

The shadow of a 4 ft. tall mailbox is 3 ft. long. If the shadow of a tree is 36 ft. long, how tall is the tree?

heightshadow

heightshadow

=

You must be careful to place the same quantities in corresponding positions in the proportion

Proportions

144 = 3HH = 48The tree is 48 ft. tall

H 36

4 3 =

Are the Ratios Proportions?

Simplify to tell whether the ratios are equivalent.

1449

B. and1636

Since ,

the ratios are

equivalent.

15 =1

515

=3 ÷ 315 ÷ 3

315

=

15

=9 ÷ 945 ÷ 9

945

=

27

=14 ÷ 749 ÷ 7

1449

=

49=

16 ÷ 436 ÷ 4

1636

=

Since

the ratios are

not equivalent.

2 7 =

49

315

A. and 945

Unit Conversions

Liquid Measures:

8 ounces (oz.) = 1 Cup16 ounces = 1

Pint32 ounces = 1

Quart64 ounces = ½

Gallon128 ounces = 1

Gallon

Dry Measures:16 ounces (oz.) = 1

pound (lb.)2000 lbs. = 1 Ton

Distance:

12 inches= 1 Foot3 Feet = 1 Yard5280 Feet= 1 Mile

Please turn to the Practice Problem section of your notebook until the end of the lesson.

Ratios vs. Rates

A ratio is the comparison of two different numbers.Solve: The basketball team won 7 games and lost 4 games. A. What is the ratio of wins to losses? B. What

Percent of its games has the team won. (What is its win Percent?)In a ratio, if the numerator and denominator are

measured in different units then the ratio is called a rate.You can travel 1200 miles on 60 gallons of gas. This rate is expressed as: 1200 miles/ 60 gal.

A unit rate is a rate in which the second quantity is 1. Like 60 miles per 1 hour. In the above example, what is the Unit? What is the unit rate?

Comparing Unit Rates

Ratios vs. Rates

Ratios Involving Measurement

WHEN A RATIO INVOLVES MEASUREMENTS, BOTH QUANTITIES MUST HAVE THE SAME UNIT OF MEASURECONVERT LARGER UNIT (FT) TO THE SMALLER UNIT (IN).

1. Express the ratio 6 feet to 15 inches as a fraction in simplest form.

2. SIMPLIFY AS A FRACTION: 3 PINTS TO 2 CUPS

*Change the larger unit to the smaller one. 3 pints = 6cups. The ratio is now 6 cups to 2 cups. Simplify to: 3/1

Six feet = 72 in. Simplify 72/15; the answer is 24/5

1. Rates Involving Two Different Measures: 10 ft./ sec. = miles/hour *Convert one unit at a time* The process is the same as finding equivalent fractions. 1st: How many seconds are in an hour? 3600Next: Set up a proportion:2. 30 yards/ minute = feet/second

Change yards to feet: 30 yds. = 90 ft.

Converting Rates & Measurement

Change minutes to seconds: 60 seconds. The ratio is now:90 ft./60 seconds. Reduce to the final answer: 1.5 ft./sec

. Class Work:Pages 62-63: Odd/Even

**Page 66: Odd; do 3, 5, 7Even; do 4, 6, 8

**Page 65: Odd; do 3, 5, 9Even; do 2, 6, 8