Percentages

​The

​A lady was purchasing a clearance item that was 40% off. There was a sale on clearance for and additional 10% off. The item was originally $10. The sales associate said the new price was $5.40. The customer argued it should be $5.

​Who is correct?

​Question

​Why do we need to understand percentages?

Multiple Choice

What percentage of the shape is shaded blue?

• 100%

• 75%

• 65%

• 50%

Multiple Choice

What percent is in color?

• 620%
• 1/2
• 60%
• 62%

​Converting between Percent, Fractions, and Decimals

0.025=

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​62%=

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​4/5=

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Multiple Choice

What fraction is equivalent to 25%?

• 1/3
• 1/4
• 1/5
• 1/8

Multiple Choice

Convert 73% to a decimal

• 73.0

• 0.37

• 0.73

• 0.7

​What is 70% of 600?

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​28 is 35% of what number?

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​What percent of 300 is 50?

Multiple Choice

What is 10% of 730?

• 73

• 7300

• 350

• 735

Multiple Choice

Calculate 25% of 400

• 100
• 16
• 200
• 150

Multiple Choice

What percent of 50 is 20?

• 40%
• 25%
• 2.5%
• 4%

Multiple Choice

34% of what number is 51?

• 69
• 71
• 150
• 196

​Discounts

• ​If an item is X% off, to find the discount, multiply the price of the item * the percent as a decimal.

• ​To find how much you pay, subtract that from the price.

• ​Shortcut: Subtract the % discount from 100. Then multiply that percent as a decimal * the price.

​Sales Tax

• ​Find the sales tax % as a decimal.

• ​Multiply by the price/total.

• ​Add to the total.

• ​Shortcut: Find the decimal for the sales tax %. Add a 1. Then multiply to find your total.

• ​Example: Sales tax 7%--> Multiply by 1.07

Multiple Choice

A St. Louis Cardinals hat costs $18.  If there is 8% sales tax, what is the total cost of the hat including tax?

• $1.44
• $22.74
• $21.36
• $19.44