M6 U4 Lesson 7 Solving Percent Problems

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 calculate a percentage of a number?

Back

To calculate a percentage of a number, multiply the number by the percentage (in decimal form). For example, to find 20% of 50, calculate 50 x 0.20 = 10.

Front

What is the formula to find the total when given a percentage and a part?

Back

The formula is: Total = Part / (Percentage in decimal form). For example, if 30 is 60% of a number, Total = 30 / 0.60 = 50.

Front

How do you convert a fraction to a percentage?

Back

To convert a fraction to a percentage, divide the numerator by the denominator and then multiply by 100. For example, 1/4 = (1 ÷ 4) x 100 = 25%.

Front

If 25% of a class of 40 students are girls, how many girls are in the class?

Back

10 girls. (25% of 40 = 0.25 x 40 = 10)

Front

What is the relationship between percentages, fractions, and decimals?

Back

Percentages, fractions, and decimals are different ways to represent the same value. For example, 50% = 0.5 = 1/2.

Front

How do you find what percent one number is of another?

Back

To find what percent one number (part) is of another number (whole), use the formula: (Part / Whole) x 100. For example, (24 / 80) x 100 = 30%.

Front

If you scored 18 out of 20 on a test, what is your percentage score?

Back

90%. (18 / 20 = 0.90, and 0.90 x 100 = 90%)

Front

What is the percent increase if a price goes from $50 to $65?

Back

30% increase. ((65 - 50) / 50) x 100 = 30%.

Front

If 40% of a number is 20, what is the number?

Back

50. (20 / 0.40 = 50)