# Knowledge Base

## Solution 10437: Performing Fraction Calculations on the TI-85 or TI-86.

### How are fraction operations calculated on the TI-85 and TI-86 graphing calculators?

The examples below will demonstrate how to add, subtract, multiply, and divide fractions on the TI-85 and TI-86:

Example: 3/4 + 7/5
1) Input 3, press [¸], and input 4
2) Press the [+] key
3) Input 7, press [¸], and input 5
4) Press the [2nd] [MATH] [F5] [MORE]
5) Select [F1] (the convert-to-fraction function)
6) Press the [ENTER] key

The result displayed should be 43/20.

Example: (25_4/7) - 9/16
1) Press [(], input 25, and press [+]
2) Input 4, press [¸], input 7, and press [)]
3) Press the [-] key
4) Press [(], input 9, press [¸], input 16, and press [)]
5) Press the [2nd] [MATH] [F5] [MORE]
6) Select [F1]
7) Press the [ENTER] key

The result displayed should be 2801/112.

Example: 8/4 x 6/15
1) Input 8, press [¸], and input 4
2) Press the [x] key
3) Input 6, press [¸], and input 15
4) Press the [2nd] [MATH] [F5] [MORE]
5) Select [F1]
6) Press the [ENTER] key

The result displayed should be 4/5.

Example: (5_8/13) / (9/23)
1) Press [(], input 5, press [+],
2) Input 8, and press [¸], input 13, and press [)]
3) Press the [¸] key
4) Press [(], input 9, press [¸], input 23, and press [)]
5) Press the [2nd] [MATH] [F5] [MORE]
6) Select [F1]
7) Press the [ENTER] key

The result displayed should be 1679/117.

For additional information and instructions on using the TI-85 and TI-86, refer to the appropriate online guidebook.