7th Grade: Percent Review

Front

What is the formula to calculate percent increase?

Back

Percent Increase = ((New Value - Old Value) / Old Value) x 100

Front

If a shirt costs $20 and is on sale for $15, what is the percent decrease in price?

Back

Percent Decrease = ((20 - 15) / 20) x 100 = 25%.

Front

What is a tip and how is it calculated?

Back

A tip is a percentage of the total bill given to service workers. It is calculated by multiplying the total bill by the tip percentage.

Front

How do you calculate the total cost including sales tax?

Back

Total Cost = Item Price + (Item Price x Sales Tax Rate).

Front

What is the formula for calculating simple interest?

Back

Simple Interest = Principal x Rate x Time.

Front

If you estimate 500 items in a package but find only 400, what is the percent error?

Back

Percent Error = |(Estimated Value - Actual Value) / Estimated Value| x 100 = 20%.

Front

What does 18% tip on a $50 bill equal?

Back

Tip = 50 x 0.18 = $9. Total = $50 + $9 = $59.

Front

What is the principal amount if $120 interest is earned at 2% over 5 years?

Back

Principal = Interest / (Rate x Time) = 120 / (0.02 x 5) = $1200.

Front

How do you convert a percentage to a decimal?

Back

To convert a percentage to a decimal, divide by 100. For example, 25% = 0.25.

Front

What is the total cost of an item priced at $30 with a 10% sales tax?

Back

Total Cost = 30 + (30 x 0.10) = $33.