Proportions Practice

Building Blocks

100

What does it mean for two ratios to be proportional?

Two ratios that represent the same relationship/value

200

Is 2/5 = 6/15 a proportion?

Yes

300

Write a proportion comparing 3 red marbles for every 5 blue marbles to 9 red marbles and X blue marbles. EXTRA: solve for x

3/5 = 9/x

x=15

400

If two ratios are proportional, what happens when you cross multiply?

The cross products are equal.

500

Create a proportion to solve: 7 tickets cost $35. How much would 12 tickets cost? EXTRA: solve for the cost of 12 tickets.

7/35 = 12/x

12 tickets cost 60 dollars

Find the Missing Number

100

2/3 = x/6

x=4

200

5/8 = 15/x

x=24

300

x/12 = 5/20

x=3

400

7/x = 21/18

x=6

500

9/15 = x/45

x=27

Scale Drawings

100

A drawing uses a scale of 1 inch = 4 feet. What does 3 inches represent?

12 ft

200

A map uses 1 cm = 5 miles. Two towns are 4 cm apart on paper. How far apart are they in real life?

20 miles.

300

A room is 20 ft long. On a scale drawing, 1 inch = 5 ft. How long should the room be on the drawing?

4 inches

400

On a blueprint, a wall is 6 inches long. The scale is 1 in = 3.5 ft. How long is the real wall?

21 ft

500

A rectangular park measures 2.5 inches by 4 inches on a drawing. The scale is 1 inch = 12 ft. What are the park's actual dimensions?

30 ft by 48 ft

Word Problems

100

2 notebooks cost $6. How much does 1 notebook cost?

$3

200

3 smoothies cost $12. How much would 5 smoothies cost?

$20

300

A car travels 120 miles on 4 gallons of gas. At the same rate, how far can it travel on 7 gallons?

210 miles

400

A recipe needs 3 cups of flour for 8 servings. How many cups are needed for 20 servings?

7.5 cups

500

8 workers can pack 240 boxes at the same rate. How many boxes would 13 workers pack?

390 boxes.

Challenge Problems

100

Are 3/4 and 9/12 proportional? Why or why not?

Yes. Their scaling factor is 3.

200

Which value makes this proportion true?

4/7 = x/21

x=12

300

Is 6/8 = 15/20 proportional? Why or why not?

Yes. Their scaling factor is 5/2.

400

A student says 5/8 makes 20/30. What mistake did they make?

The top scaling factor is 4 where the bottom scaling factor is 15/4. When scaling fractions to keep them proportionate, they must be multiplied numerator and denominator by the same scaling factor.

500

A square drawing uses 1 cm = 6 m. A rectangular playground measures 7.5 cm by 4 cm. What is its actual area?

The actual dimensions are 45 meters x 24 meters. This makes the area 1,080 meters²

^{Don't forget the squared!}