A decimal can be useful for calculations, but a fraction is often easier to read in an algebra or math problem. A value such as 0.75 can be written as 3/4, while 0.125 can be written as 1/8. You can convert decimals to fractions directly on a TI-84 calculator without doing the conversion manually.

The TI-84 Plus and TI-84 Plus CE include built-in commands that can change a decimal result into a fraction when the calculator can recognize the value. The process requires only a few buttons. You can also use the calculator to check whether a decimal has an exact fractional form or whether the displayed result is only an approximation.

How to Convert a Decimal to a Fraction on a TI-84

The easiest method is to enter the decimal and use the MATH menu. The TI-84 provides a command called â–ºFrac that converts a number into a fraction.

Follow these steps:

  1. Turn on your TI-84 calculator.
  2. Press the MATH button.
  3. Select 1:â–ºFrac.
  4. Enter the decimal number.
  5. Press ENTER.
  6. Read the fraction displayed on the home screen.

For example, suppose you want to convert 0.75 into a fraction.

Press:

MATH → 1:â–ºFrac

Then enter:

0.75

Press ENTER.

The calculator displays:

3/4

This method works well for simple terminating decimals.

Convert 0.5 to a Fraction

The decimal 0.5 is equal to one-half. You can use the â–ºFrac command to convert it.

Enter:

0.5

Then apply the fraction command:

MATH → 1:â–ºFrac → ENTER

The result is:

1/2

The calculator automatically reduces the fraction to its simplest form.

Convert 0.25 to a Fraction

The decimal 0.25 represents one-quarter.

Use:

MATH → 1:â–ºFrac

Enter:

0.25

Press ENTER.

The TI-84 displays:

1/4

You do not need to manually multiply the decimal by 100 or simplify the resulting fraction.

Convert 0.125 to a Fraction

The decimal 0.125 is equal to 1/8.

Enter the decimal and use â–ºFrac:

MATH → 1:â–ºFrac → 0.125 → ENTER

The result is:

1/8

This example shows why the calculator can save time when working with several decimal values.

Convert a Decimal Result to a Fraction

You can also convert the result of a calculation. This is useful when the decimal comes from an equation rather than a number that you entered directly.

For example:

1 ÷ 4

Press:

1 ÷ 4 → ENTER

The calculator normally displays:

0.25

You can then convert the result by using:

MATH → 1:â–ºFrac → ENTER

The result becomes:

1/4

You can use the same process for calculations involving addition, subtraction, multiplication, or division.

For example:

0.5 + 0.25

Press ENTER to calculate the result.

The calculator gives:

0.75

Then use â–ºFrac to get:

3/4

How to Use the â–ºFrac Command

The â–ºFrac command is located in the TI-84 MATH menu. The arrow in â–ºFrac means that the calculator converts the value on the left into a fractional form.

You do not need to type the command manually.

Use these buttons:

MATH → 1

The TI-84 inserts â–ºFrac on the calculator screen.

You can then enter the decimal number and press ENTER.

For example:

MATH → 1 → 0.625 → ENTER

The result is:

5/8

The calculator simplifies the fraction automatically.

How to Convert Decimals Using the ANS Key

The ANS key can help when you have already calculated a decimal.

Suppose you calculate:

7 ÷ 8

Press ENTER.

The calculator displays:

0.875

Instead of entering 0.875 again, you can use the previous answer.

Press:

MATH → 1 → 2nd → ANS → ENTER

The calculator applies â–ºFrac to the previous result.

The answer is:

7/8

This method is useful when the decimal is the result of a longer calculation.

How to Convert a Repeating Decimal to a Fraction

Repeating decimals require more care. A value such as 0.333333… represents 1/3, but the TI-84 cannot display an infinite number of repeating digits on the screen.

If you enter a rounded value such as 0.3333333333, the calculator may not always return exactly 1/3 because the number you entered is an approximation.

For example, enter:

1 ÷ 3

The calculator displays a decimal approximation.

You can then try:

MATH → 1:â–ºFrac

The TI-84 may return a fractional result based on the calculator's internal value.

For exact fractions, it is better to keep the original calculation when possible rather than manually entering a rounded repeating decimal.

Why Does the TI-84 Sometimes Not Give the Expected Fraction?

The â–ºFrac command does not turn every decimal into a simple fraction that looks familiar. The result depends on the number stored by the calculator and its ability to represent the value as a fraction.

For example, a terminating decimal such as 0.75 has an exact fraction:

3/4

However, a number such as 0.3333333333 is not exactly 1/3. It is a finite decimal approximation of 1/3.

A decimal can also come from a calculation that produces an irrational number. Values involving numbers such as π or square roots may not have a simple exact fraction.

For these values, the calculator may display a fraction that represents an approximation or may retain the decimal representation.

How to Convert a Fraction Back to a Decimal

You can also convert a fraction into a decimal on a TI-84.

Use the â–ºDec command from the MATH menu.

For example, enter:

3/4

Then use:

MATH → 2:â–ºDec → ENTER

The calculator displays:

0.75

This lets you move between fractional and decimal forms when checking your work.

Decimal to Fraction Examples

The following examples show common decimal-to-fraction conversions:

DecimalFraction
0.51/2
0.251/4
0.753/4
0.21/5
0.42/5
0.63/5
0.84/5
0.1251/8
0.3753/8
0.6255/8
0.8757/8

You can verify each value on the TI-84 by entering the decimal and applying â–ºFrac.

What to Do When â–ºFrac Does Not Work

If the calculator does not produce the fraction you expect, check the value that you entered.

Make sure the decimal is entered correctly. A missing digit can produce a different fraction.

Also check whether the decimal is rounded. For example, 0.333333 is not exactly equal to 1/3.

If the value came from a calculation, use the original calculation instead of manually typing the rounded decimal. The original calculation may contain more accurate information than the number shown on the screen.

You can also try converting the answer stored in ANS rather than entering a rounded value again.

Does This Work on the TI-84 Plus CE?

Yes. The decimal-to-fraction process works on the TI-84 Plus CE as well as other TI-84 models that include the â–ºFrac command.

The menu appearance can differ slightly between calculator versions, but the main process remains the same:

MATH → â–ºFrac → number → ENTER

The TI-84 Plus CE also provides the â–ºDec command for converting a fraction back to decimal form.

Quick TI-84 Decimal to Fraction Steps

Use this sequence when you need a quick conversion:

  1. Enter the decimal.
  2. Press MATH.
  3. Select 1:â–ºFrac.
  4. Press ENTER.
  5. Read the fractional result.

For a previous calculation:

  1. Calculate the problem.
  2. Press MATH.
  3. Select 1:â–ºFrac.
  4. Press ENTER.

For example:

0.875 → MATH → 1:â–ºFrac → ENTER → 7/8

The TI-84 can reduce many terminating decimals to their simplest fractional forms. However, rounded or repeating decimal values may require the original mathematical expression for an exact result.