7th Grade- Percents

Front

What is a percent?

Back

A percent is a ratio that compares a number to 100. It is often used to express how much of something there is in relation to a whole.

Front

How do you convert a percent to a decimal?

Back

To convert a percent to a decimal, divide the percent by 100. For example, 7% becomes 0.07.

Front

What is the formula to calculate the tip based on a percentage?

Back

Tip = Total Bill × (Tip Percentage / 100). For example, for a $45.80 bill and a 20% tip, the tip is $45.80 × 0.20 = $9.16.

Front

What is 20% of 50?

Back

20% of 50 is 10.

Front

How do you find a percentage of a number?

Back

To find a percentage of a number, multiply the number by the percentage (as a decimal). For example, to find 12% of 40, calculate 40 × 0.12 = 4.8.

Front

What is the formula for calculating simple interest?

Back

The formula for simple interest is I = PRT, where I is interest, P is principal amount, R is rate (as a decimal), and T is time in years.

Front

If you invest $1,000 at an interest rate of 5% for 3 years, how much interest will you earn?

Back

You will earn $150 in interest. (I = 1000 × 0.05 × 3 = 150)

Front

What is the total amount in the account after earning interest?

Back

Total Amount = Principal + Interest. For example, if you invest $1,000 and earn $150 in interest, the total amount is $1,150.

Front

How do you calculate the interest rate if you know the interest earned, principal, and time?

Back

You can rearrange the simple interest formula: R = I / (PT). For example, if you earned $100 on $800 over 5 years, R = 100 / (800 × 5) = 0.025 or 2.5%.

Front

What is 6% of 200?

Back

6% of 200 is 12.