ATI TEAS GUIDE TO MATH | BASIC PERCENTAGES -

UNDERSTANDING PERCENTAGES

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QUIZ QUESTIONS LISTED AT END OF REVIEW

The ATI TEAS will ask the applicant to determine the increase or decrease in percentage as represented by certain numbers. In addition, the applicant can be asked how to calculate percentages into final numbers when provided an operation about a specific percentage change.

HOW TO CALCULATE PERCENTAGES

To begin, we must understand what percentages are and how to calculate them. A percentage is a portion of an amount. Percentages can be expressed in two different ways. Either by a fraction (10/100) or written as 10%.

Simplify the operation: What is 10% of 200?

To perform the operation, we must multiply the number by the percentage given. We must first turn the percentage into a decimal. Start with 10% and move the decimal point to the left two places.

10% = 0.10

Once the percentage is converted to a decimal, you may multiple the operation.

200 x 0.10 = 20

The correct answer is 20.

Percentages can also be greater than 100 and are performed the same.

Simplify the operation: What is 300% of 15?

First, we begin by converting the percentage a decimal number. We move the decimal point to the left two places.

300% = 3.00

Lastly, we multiple 15 by 3.

15 x 3 = 45

The correct answer is 45.

Percentages can also be less than 1 and are performed the same.

Simplify the operation: What is 0.20% of 200?

First, we begin by converting the percentage into a decimal number only. We move the decimal point to the left two places. Be careful with these equations since the percentage is already a decimal.

0.20% = 0.0020

Since the percentage was already a decimal, we simply added two zeros to the right of the decimal.

Next, we multiple 200 by 0.0020.

200 x 0.0020 = 0.4

The correct answer is 0.4.

UNDERSTANDING INCREASES AND DECREASES WITH PERCENTAGES

As stated previously, another kind of operation likely to be found on the ATI TEAS involves increasing and decreasing with percentages.

For example: A computer went on sale for 30% off its original price. The original price is $1060. What is the new sale price?

This operation is asking the applicant to find the decrease percentage of a given quantity. To begin, we must first convert the percentage into a decimal.

30% = 0.30

Now we can multiple $1060 by 0.30 to determine the amount of the sale.

$1060 x 0.30 = $318

Finally, we can subtract the amount of the sale from the original price.

$1060 – $318 = $742

The sale price for the computer is now $742.

If you are looking to save time and your brain, there is another way to perform this operation without the extra step.

We have already established that the computer is 30% off its original price. This means the store is still charging 70% of the computer’s original price.

To begin, we must first convert the percentage into a decimal.

70% = 0.70

Now we can multiple $1060 by 0.70 to determine the amount of the sale.

$1060 x 0.70 = $742.

The ATI TEAS will also test the applicant on how to perform increase percentage operations on given quantities.

For example: A retail store increases its monthly sales from $2,000 to $4,000 in one month. What is the percentage increase in sales for the retail store?

To begin, we must first determine how much more money the retail store made in one month. We will subtract the previous month’s sales ($2,000) from the current month’s sales ($4,000).

$4,000 – $2,000 = $2,000

The total sales increase amount is $2,000. Now, we must determine what the percentage increase is by performing the following operation.

The amount of increase we calculated is $2,000 and the original amount is $2,000 .

The percentage increase is 1 which is converted to 100% after moving the decimal to the right two places.