TEAS Math: Percent Increase, Decrease, and Percentage Problems

There are four basic skills that are tested in most TEAS math involving percent problems, and it can be difficult to find the original value when the value changes by a percentage. Students who know how to find 20% of 80 will likely have a difficult time with a word problem that alters the equation. These questions can be easier to tackle if you know the meaning of the words, the appropriate formula, and can verify the answer. Go through 20% of 80, understanding each type of problem and why the denominator is important.

The Four Families of Percent Problems

All percent problems can be classified into four types. If you know what the category is, the right calculation will be selected.

Don’t confuse these two setups with similar numbers, as they are different questions. In word problems, the word is means equals, the word of ” usually means multiply, and what percent is a rate out of 100. TEAS math: Practice turning sentences into equations before calculating. This strategy is particularly helpful when a question includes multiple pieces of information and/or how to turn the sentence into an equation.

Percent Change: The Denominator Trap

The formulas for percent increase and percent decrease are alike – they both involve dividing the amount of increase or decrease by the original amount.

Percent increase: (New value − Original value) ÷ Original value × 100

Percent decrease: (Original value − New value) ÷ Original value × 100

Suppose that a group of 40 students increases to a group of 50 students. What is the percent increase?

Wrong: (50 − 40) ÷ 50 × 100 = 20%.

Correct: (50 − 40) ÷ 40 × 100 = 25%.

The wrong answer is given when the value is divided. While 50 is the bigger number, the question is asking about growth from the starting point. This confusion with a denominator can lead to unnecessary percent problems.

When working out percent change questions, make sure you know the original value first. If it appears too small, make sure to look at your denominator first!

Successive Percents Multiply, They Don’t Add

If I increase the value by 20% then decrease the value by 20%, does that bring the value back to its original value? No. Each percent is used on a different size.

Start with 100. A 20% increase raises it to 120. If the number of hacks is reduced by 20%, there will be 96 left.

This can be explained with the help of the multiplier method:

Increase by 20%: multiply by 1.20.

Decrease by 20%: multiply by 0.80.

Combined change: 1.20 × 0.80 = 0.96.

The final amount is 4% less than the original amount. In the same way, if the initial number is 100, and then it is percent increased by 50%, then percent decreased by 50%, the resulting number is 75.

Discounts, taxes, and other successive changes can be included on the same questions in TEAS math. Use the correct factors, rather than adding or subtracting the percent.

Reverse Percent: Finding the Original Value

To determine the original value when percent change has happened, you need to reverse the multiplier – not the percentage from the final figure.

What is the number if it’s increased by 20% to become 60?

To find 20% of 60, subtract 20% from 60 to get 48. The original percentage, however, was based on the amount at the beginning.

Correct: 60 = 1.20 × Original value.

Therefore, 60 ÷ 1.20 = 50.

Verify the answer: 50 increased by 20% is equal to 60. If the answer is 48, it would only increase to 57.60 with the same increase.

Divide the remaining amount by the amount that has been decreased. If a value decreases by 25% and becomes 45, calculate 45 ÷ 0.75 = 60.

This method can be used to correctly solve reverse percent problems without guessing or using the wrong base for the percent.

Percent vs Percentage Points

Percent changes are expressed as percentage points. Percent change tells how much something changes in percentage terms compared to the percent at the beginning.

For instance, when the average pass rate increases from 40% to 50%.

Percentage-point increase: 50 − 40 = 10 points.

Percent increase: 10 ÷ 40 × 100 = 25%.

Either answer is correct, but they are talking about different concepts. Carefully read the question on page 5 before choosing an answer, especially if both numbers are in the options in TEAS math.

Set Up First, Then Use the Calculator

The TEAS math section includes an onscreen calculator that you can use to add, subtract, multiply, and divide. It lacks a percent key and brackets, so you must use your own logic in structuring calculations.

Follow three steps:

• Enter numbers before writing the equation.
• Make an estimate to help detect misplaced decimals.
• Use the calculator to work out the answers to the percent problems, NOT to determine which formula is to be used.

With a bit of practice, one can develop confidence with simple percents without shortcuts for each question. Take the time to determine the proper setup rather than continually keying in numbers.

Where Percent Problems Hide on the TEAS

Percent problems might be presented in measurement problems, in tables, graphs, in science questions, or in ratio problems in word problems. The question might not just involve calculating a simple percent, but require you to compare two measurements or interpret an increase or decrease in concentration.

Practice percents within the word problem in preparation for the different formats. An online TEAS math practice test will also assist you in determining which configurations to review more.

Frequently Asked Questions

What is the formula for percent increase on the TEAS?

Subtract the original value from the new value, then divide the difference by the original, and multiply by 100.

How do I find the original value after a percent change?

Divide the end value by the right-hand number rather than subtract the percentage.

Does a 20% increase followed by a 20% decrease cancel out?

No. The changes result in 120 and then 96 starting from 100.

Is there a calculator on the TEAS math section?

Yes. The four-function calculator can be used for arithmetic, but it must be set up properly.

Conclusion

The ability to solve percent problems involves identifying the type, checking the denominator, and undoing changes by dividing and multiplying successive percent changes. Apply these techniques to word problems to become more confident and accurate. A structured online TEAS Practice Test can help you gauge your progress with TEAS math and prepare better.