TABE Level D Math: Percents

Percents are all around us. A department store has a 15% off sale. You can finance a car for 5% interest. A basketball player has a 46% shooting average. You score 80% on your test. In all these examples, percent is a way of measuring part of a whole. The department store sale saves you part of the whole cost of what you buy.

The interest is the part of the total amount of money you borrow that you have to pay back (in addition to repaying the borrowed money!) The free throw average is the part of all the free throws the player takes. The test score is part of all the questions that you got right.

Percents give you an idea of how much of the whole the part is, regardless of how many things there are or what they are. A score of 80% on a test could be 8 correct answers out of 10 questions or 20 correct out of 25 questions. A 46% shooting average could be 46 shots made out of 100 taken, or 23 made out of 50 taken. The 15% off sale could mean that you save $4.50 on a $30 jacket or $75 on a $500 TV set. This is because the part is standardized to a whole of 100.

There are three types of percent problems in this section of the TABE D.


1. The problem tells you the whole and the part, and you have to find the %.

2. The problem tells you the whole and the %, and you have to find the part.

3.The problem tells you the part and the %, and you have to find the whole.

In other words, you are told 2 of the 3 amounts, and you have to find the third.

There is a formula for each of these:



Once you’ve memorized these formulas, you need to be to determine which 2 numbers a problem tells you. 

The number that is in front of the % sign is the %. The number that comes after the word “of” is the whole. The number that comes after the word “is” or “ = ” is the part.

Let’s look at an example of each of these.

Example A. What is 20÷ of 50?
The problem tells you the ÷ and the whole, so use the formula for the part:

Part = . 20÷ of 50 is 10.

Example B. What percent of 30 is 12?
The problem tells you the whole and the part, so use the formula for the %:



Example C. 3 is 30÷ of what number?
The problem tells you the part and the %, so use the formula for the whole:




Practice Percent Problems


1. Find 12% of 50.

2. What percent of 20 is 9?

3. 10 is 25% of what number?

4. What percent of 10 is 7?

5. 15% of what number is 9?

6. 8% of 300 = ?

7. What percent of 18 is 9?

8. 12 is 20% of what number?

9. 7 is 25% of what number?

10. Find 90% of 150.

Answers: Practice Percent Problems

1. 6

2. 45%

3. 40

4. 70%

5. 60

6. 24

7. 50%

8. 60

9. 28

10. 135