# GRE Math : Decimals and Percentage

## Example Questions

### Example Question #9 : Percentage

Robert has  of his cereal left.  Choose the answer which best expresses as a decimal, how much of his cereal he has eaten.

Explanation:

The easiest way to convert between percent and decimal is to first convert the percentage into a fraction:

Then, from the fraction, you can convert quite easily to a decimal:

HOWEVER--in this problem, they are asking you for the portion that makes up the rest of the cereal--so you need to subtract your decimal above from , which yields the correct answer:

### Example Question #1 : Percentage

Choose the answer below which best expresses the following as a decimal:

Explanation:

When converting percents into decimals, know that the tens and ones digit of the percent will occupy the tenths and hundredths places of the decimal.  Any decimal following the whole percent will follow in sequence (i.e. the first decimal place in a percent corresponds to the thousandth place, and so on).  Therefore, ninety-seven point five percent is equal to:

### Example Question #11 : Percentage

Choose the answer which best expresses the following percentage as a decimal:

%

Explanation:

To convert a percentage into a decimal, simply place the decimal point in front of the tens digit of the percentage.  So, % becomes .

### Example Question #12 : Percentage

Choose the answer below which best expresses the following decimal as a percent:

Explanation:

To convert a percent into a decimal, simply know that the tenths place of the decimal will correspond to the tens digit of the percent, and the thousandths place of the decimal will correspond to the ones digit of the percent. Any ensuing digits will be behind a decimal in the final percent.

Also converting a decimal to a percent can be accomplished by multiplying the percent by 100.

Therefore, the best answer here is:

### Example Question #13 : Percentage

Choose the answer which best expresses the following decimal as a percentage, rounded to the nearest tenth of a percent if necessary:

Explanation:

To express a decimal as a percent, multiply the decimal by one hundred:

### Example Question #14 : Percentage

Choose the answer which best expresses the following decimal as a percentage, rounded to the nearest tenth of a percent if necessary:

Explanation:

To express a decimal as a percent, multiply the decimal by one hundred:

### Example Question #15 : Percentage

Choose the answer which best expresses the following decimal as a percentage, rounded to the nearest tenth of a percent if necessary:

Explanation:

To express a decimal as a percent, multiply the decimal by one hundred:

### Example Question #1 : How To Find Percentage Equivalent To A Decimal

Choose the answer which best expresses the following decimal as a percentage, rounded to the nearest tenth of a percent if necessary: