Unit 5 Test Corrections application of proportion

Rate per 1 of something. EX:
miles per hour
price per pound

Use division to get a denominator of 1.

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Unit Rates

Unit Rates can be decimals.
This bag of ice costs $2.99. What is the unit rate?

Fill in the Blanks

A 20 lbs. bag of flour costs $13.00 at Costco. Use a calculator to find the unit rate,

$

per pound (enter just the number in the blank)

scale factor -  is the ratio between corresponding measurements of an object and a representation of that object

​Reduction. Scale factor is a fraction between 0 and 1. (divided by 2 = times 1/2)

Poll

Find the scale factor of the enlargement from Y to X

• 1/2

• 3

• 2

• 4

Multiple Choice

The pair of figures is similar. Find the missing side.

• x = 10
• x = 4
• x = 2
• x = 5
• I'm not sure.

Multiple Choice

Find missing side

• 5
• 7
• 9
• 11

Multiple Choice

The scale drawing car length is 3 cm. If the scale is 1 cm:4 ft, what is the actual car length?

• 12 feet
• 16 feet 
• 10 feet
• 4 feet

All side lengths of the real figure are proportional to the drawing.
All measurements are multiplied or divided by the same number (scale factor)

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Scale Drawings

Poll

A scale drawing of a flagpole has a scale of 1 in.= 4 ft. If the drawing of the pole measures 12 inches, how tall is the actual pole?

• 16 feet
• 3 feet
• 48 feet
• 9 feet

Multiple Choice

Scale is 1cm = 8km. Hatboro and Smithville are 24cm apart on the map, what is the actual distance between the 2 cities?

• 87 km
• 216 km 
• 33 km
• 192 km

Poll

How are you doing?

• Good! I'm getting these right.

• Pretty good! I'm getting some of these right.

• Just okay. I feel like I'm getting a lot of these wrong.

Tax and Tip are a percent of the cost that is added on.
Commission is a percentage of the cost paid to the salesperson or agent by their company, like a tip from the boss.

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Tax and Tip
Commission

Multiple Choice

What is 25% as a decimal?

• 2.5

• 0.25

• 0.025

• 250

Multiple Choice

What is 2% as a decimal?

• 20

• 0.2

• 0.02

• 200

Basics:
1. Convert the rate to a decimal (50% = 0.50 move decimal 2 places left)
2. Multiply the total by that decimal. Use a calculator.
3. Add that to the price for a tip or tax. Subtract it for a discount (on sale).

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Find a Percentage

Multiple Choice

What is 20% of $100?

• $200
• $50
• $10
• $20

Multiple Choice

What is the total if you leave a 20% tip for a waiter? Your bill was $100.

• $200
• $150

• $110

• $120

How much did it change?
100% change means the price doubled.
-50% change means half off.

​Use a calculator.

Percent of Change

Multiple Choice

Find the percent change.
Original amount:  10
New amount: 12

• 20%
• 12%
• 15%
• 50%

Multiple Choice

Your family drives 200 miles in 4 hours. What is their unit rate? (hint, this is their miles per 1 hour which we usually just call their speed)

• $$\frac{50}{1}\ miles\ per\ hour$$

• $$\frac{1}{50}\ miles\ per\ hour$$

• 800 miles

• 5 miles per hour

1. Find the difference between the estimate and the real value.

2. Divide by the real value.

3. x100.

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Percent Error? That's a percent of change.

Multiple Choice

You estimated that 100 people would come to the field trip. Only 80 people came. What was the percent error?

• 25
• 20
• 10
• 50