Ratios Rates Solving Proportions Proportions Scale Drawings Percents

Ratios

Rates

Solving Proportions

Proportions & Scale Drawings

Percents, Decimals, & Fractions

Finding a Percent of a Number

$100 $200 $200 $100 $200 $300 $300 $400 $400 $500 $500

Write the ratio two other ways

5: 12 5 to 12

Write the ratio in simplest form

Complete the following statement =

7 x 6 = 42 42 ÷ 21 = 2 X=2

Counselors 2 3 x Campers 16 24 32 What is the ratio of counselors to campers in simplest form?

Counselors 2 3 x Campers 16 24 32 Solve for x

= 32 x 2 =64 64 ÷ 16 = 4 x=4

Are these rates equivalent? and

36 x 5 =180 90 x 2 = 180 Yes, these rates are equivalent

= Solve for y

16 x 3 = 48 48 ÷ 4 = 12 y = 12 oz.

Are these rates equivalent? and

8 x 3 = 24 12 x 4 = 48 No, these rates are not equivalent

Solve for the unit rate~ 20 words read in 5 minutes

= 20 x 1 = 20 20 ÷ 5 = 4

A 12 oz. tub of popcorn costs $3. A 20 oz. tub of popcorn costs $4. Which size is the better buy?

= = 3 x 1=3 3 ÷ 12 =. 25 4 x 1=4 4 ÷ 20 =. 20 The 20 oz. tub is the better buy because it costs. 20 for 1 oz.

Do these ratios form a proportion? ? =

25 x 8 = 200 10 x 20 = 200 Yes, these ratios form a proportion

Do these ratios form a proportion? ? =

18 x 3 = 54 12 x 5 = 60 No, these ratios DO NOT form a proportion

Solve the proportion =

20 x 12 = 240 ÷ 4 = 60 So, x = 60

Solve the proportion =

36 x 10 = 360 ÷ 24 =15 So, g = 15

You and a friend got the same grade on your quizzes. You got 6 out of 8 questions correct. If your friend’s quiz had 12 questions on it, how many did your friend get correct?

= 12 x 6 = 72 72 ÷ 8 = 9 So, q = 9. Your friend got 9 out of 12 questions correct.

If I have a scale of 1 in. : 3 ft. , find the actual length of a car if the length is 8 in. on the scale drawing.

= 8 x 3 = 24 24 ÷ 1 = 24 The actual length of the car is 24 ft.

The perimeter of a drawing is 8 in. The perimeter of the actual mural is 72 ft. What is the ratio of perimeters? 30 ft. 3 in. P = 8 in. 1 in. P = 72 ft. 6 ft.

(Perimeter of drawing) (Perimeter of mural) Simplify!

The area of a drawing is 2 in. 2 The area of the actual mural is 200 ft. 2 What is the ratio of the two areas? 20 ft. 2 in. A = 2 in. 2 1 in. A = 200 in. 2 10 ft.

2 (Area of drawing) 2 (Area of mural) 2 Simplify! 2

A map uses the scale of 2 in. : 50 mi. Find the actual distance for the given distance: 8 inches

= 50 x 8 = 400 ÷ 2 = 200 So, d = 200 miles

Find the ratio of drawing’s area to the garden’s area. 50 ft. 5 in. 40 ft. 4 in. Drawing Garden

Area of drawing: 5 x 4 = 20 in. 2 Area of garden: 50 x 40 = 200 ft. 2 2 = 2

You have 43 out of 100 marbles that are red. Write this ratio as a percent, decimal, and a fraction.

43% . 43

Six out of 100 people like spiders. Write this ratio as a percent, decimal, and a fraction.

Change the following fraction into a percent:

= 100 x 3 = 300 ÷ 25 = 12 So, your answer is 12%

Write the following decimal as a percent: 0. 08

Write the following decimal as a percent: 0. 4

= 100 x 4 = 400 ÷ 10 = 40 So, 0. 4 = 40%

What is 25% of 60?

Decimal way: . 25 x 60 = 15 Fraction way: x 60 x 25 = 1500 ÷ 100 = 15

The regular price of a DVD is $20. The sale price is 15% off. How much money will you save?

15 % of $20. 15 x 20 =$3 You will save $3.

The price for a Wii is $200. Target has them 40% off. What is the sale price?

40% of $200. 40 x $200 = $80 You will save $80. To find the sale price… $200 - $80 = $120

You are buying a tire for your car that costs $49. There is a 6% sales tax. What is the total amount of your purchase?

6% of $49. 06 x $49 = $2. 94 Your sales tax is $2. 94 To find the total amount of your purchase…. $49 + $2. 94 = $51. 94

You are buying a new controller for your Wii that costs $29. There is a 6. 75% sales tax. What is the total amount of your purchase?

6. 75% of $29. 0675 x $29 = $1. 96 Your sales tax is $1. 96 To find the total amount of your purchase…. $29 + $1. 96 = $30. 96

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