Calculating Percents with TI-30 XS

In this lesson, we’ll explain how to calculate percents and convert decimals to percents and vice versa with the Texas Instruments model TI-30 XS. This lesson is part of our free online GED® classes.

The TI-30 XS is the only calculator allowed on the GED exam and knowing how to use it effectively will definitely boost your GED Math score!

Our free online GED classes are perfect to get ready for the real GED test and efficiently.

On the Math test, there will be a few questions that involve percents.

In this video, you will learn how to solve basic percent problems.

For example, find 25% of 100.

First of all, you need to know that, “of”, means times. So we need to type 25% times 100.

The percent sign is located above the left parenthesis button, so we will need to use the 2nd button to activate the additional function of this key.

Let’s get started.

Press 25 and then Press 2nd.

Now we can press the left parenthesis sign to activate the calculation of percentages.

Press times for multiplication.

And now Press 100.

Finally press enter.

And here is our result. 25% of 100 equals 25.

Step-By-Step Explanation

1. What number is \(22.4 \% \) of \(125?\)

Question 1 of 2

2. What number is \(159\%\) of \(185?\)

Question 2 of 2


On the test, there will be a few questions asking for converting decimals to percent, or the other way around.

This type of math problem is a piece of cake for your calculator when you use the convert to percent key.

The convert to percent key is in green, and it’s located above the right parenthesis.

It means that it works in combination with the 2nd key.

So let’s see how it works.

Step-By-Step Explanation

Here is the task: Convert 8.52 to a percent.

Type 8.52 and press enter. Now press the second key, and choose this button.

Press enter. And here is our result. 8.52 equals 852%.

That was easy, right?

Let’s now convert 28% to a decimal.

To input a percent, we need to use the percent symbol that is in green and above the left parenthesis key, so we will also need to use the second key to activate its function.

Type 28, then 2nd, and now this key and then punch enter.

The calculator immediately converts 28% to a decimal, and the screen shows that 28% equals 0.28.

So this concludes our lesson related to calculating percents and converting percents to decimals and decimals to percents. This lesson is included in our free online GED classes and is part of our free TI-30 XS Calculator Series.

You can continue with the following lesson about Calculating Fractions with the TI-30 XS if you click on the link above. You may also benefit from our other free online GED classes that cover the four GED subject fields of Science, Language Arts, Math, and Social Studies.


Last Updated on April 6, 2021.

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