How do i convert a decimal answer to fraction format on a TI 89 titanium.... prefferably with matrixes

None of these solutions answer his question. When converting a fraction or any number with decimal places to Binary, the TI-89 gives "Error: Domain error." For example, entering .6875 [2ND][MATH][BASE][BIN] does not work. I haven't found a way to do it with built in functions. In order to do these types of conversions, I use the following method.

Convert: 0.6875 to Binary
- left of decimal is a 0, so write down a 0, then a decimal point: (0.)
- multiply .6875 x 2 = 1.375 left of decimal is 1, write a 1: (0.1)
- drop the 1 and multiply .375 x 2 = .75 left of decimal is 0. write a 0: (0.10)
- multiply .75 x 2 = 1.5 left of decimal is 1, write a 1: (0.101)

- drop the 1, multiple .5 x 2 = 1. left of decimal is 1, write a 1: (0.1011).
- since there is no more fraction, the final answer is (0.1011). Hope this helps.

http://education.ti.com/downloads/guidebooks/graphing/89ti/TI-89_Guidebook_EN.pdf

that should be the TI 89 Titanium guide

Hi william_kien,

The Ti 89 solves a lot of fraction problems by being in the right mode and, the use of several commands. One of my first problems here at Fixya was to find a solution for, "How do i convert a decimal answer to fractions prefferably with matrixes."

Here the problem was solved just by being in the EXACT mode.

Another fraction nightmare, so I thought was to solve for, "I want to solve a Binomial Theorem problem!" You have to go to the end of the problem but, I solved it just by the use of the expand command.

The best way to display fraction is in Pretty Print and, in the EXACT mode. Here is a small demonstration of the 3 mode setting in the Ti 89 and, the effect of each to the way a fraction is displayed.

This is a demonstration of the Ti 89 simplifying and, displaying in fractional form in the AUTO mode.

This is a demonstration of the Ti 89 making numbers proper and, displaying them in fractional form while in the EXACT mode.

This demonstration of the Ti 89 not even converting in fractional form and, displaying in the APPROX mode.

You should always use parentheses when entering equations or, fractions into the calculator. Pictured just below you can see how the Ti 89 can miss-interpret what is being entered.


The propFrac command is a great tool to reducing to the simplest form.
propFrac(expression,var). This will return an expression as a
proper expression




Sometime with joining or, combining fractions you have to get the common denominator. As you can see below the comDenom command is a great tool for that.


The Ti 89's ability to compute fractions is only limited to the ability and, knowledge of the person using it. Even though, it has a tendency of making a not so, mathematically inclined person look like they have been doing them all there life.

I just gave several ways I go about solving and, displaying fractions. The best way to display fraction is in Pretty Print and, in the EXACT mode. Sometimes that isn't even enough and, you have to use parentheses and, commands to do the job.

If you want to convert a single value, press Diamond then ENTER.

If you want them all in decimal, press MODE, scroll down to Exact/Approx, and change the setting to suit.

If you leaf through the manual with its 500 some pages you will diuscover that your last statement is not quite right.
The "problem" is that the calculator is configured to perform EXACT calculation where fractions are kept as fractions and radicals as radicals.

To have your fractions displayed as decimal numbers ALL THE TIME
Press [MODE][F2]
Use Arrow down to highlight [Exact/Approx
Use right arrow to unfold the menu list and select [3:Approximate]

Press [ENTER] to save configuration

There are two other ways to convert an exact result into an approximate one

1. If you enter 25./3 or 25/3. or 25/3. and press [ENTER] the fraction will be displayed as a decimal number (The dot is a decimal mark, and it instructs calculator to perform approximate calculations)
2. If enter 25/3 without the decimal marks and press [Diamond][ENTER] the result will be decimal.

Here is what you do:

1) Press the Mode button.
2) Scroll down the list that appears until you find "Exact/Approx".
3) Change the setting for "Exact/Approx" to Exact.
4) Press enter to save the settings change.

You have three possible settings for "Exact/Approx":
1) Auto - The calculator will try to determine the best format.
2) Exact - The calculator will always give the answer in fraction form.
3) Approximate - The calculator will always give the answer in decimal form.

This is what I did. Go to Math/ 9.Algebra/ 5.approx(

Are you using a ti-89? If so, check your mode settings and change Exact to Approximate.

you can also go press the 'mode' button, and go down until you're at 'Exact/Approx' and choose '3: Approximate'

Press Diamond Enter to convert fractions to decimals.