How do I get my TI-83 Plus to show a fraction instead of 1.524157903 E -4?

Question

For instance, I type the following into my calculator:

(1/3)^8

It then spits back at me a long number to a power of ten:

1.524157903 E -4

I would like to view this number as a fraction, but selecting it as a fraction from the MATH menu does not work. It also does not help to change the mode of the calculator.

I know that the number CAN be written as a fraction (1/6561). I just need to know how to arrive at that.

Answer 1

The TI - 83 doesn't automatically do what you are asking.

one trick that will help you get fractions that are of the type 1/### is to use the X^-1 button, on the answer to give you the denominator.

Answer 2

Hi,

The TI-83 Plus manual says that fractions are limited to those with denominators with no more than 3 digits. But I think it's more accurate to say that it will not do fractions with decimal equivalents of less than .001. For example it wil return the answer for 12/6000 as 1/500 using the MATH->Frac technique.

If the fraction has 1 as a numerator, you can always use the inverse button (x with -1 written as an exponent) to get the denominator. But if the numerator is a number other than 1, then you could get a whole number plus a decimal.

Sometimes when you do this you can figure out what number will cause the number found by the inverse method to be a whole number.

Let's take as a simple example 6/10000, which is displayed on the calculator as 6E-4. Press 2ND, Ans; then the inverse button you'll get 1666.666667. Well, you can guess that that's 1/6th of 10000. So, press 2ND, Ans, *, 6, and you'll get 10000. So, that tells you that the numerator is 6 and the denominator is 10000.

Enough of this stuff. You're probably sorry you asked. :-)

FE

Answer 3

Type in:



(1/3)^8 ΔFRAC



The ΔFRAC operator can be found under "MATH".



If you find that the denominator is (allegedly) too big for the Ti83 to find, type in your expression, and then type:



1/Ans ΔFRAC



That will give you b/a, if a/b is your fraction. Other than that, there's no way to find the fraction unless you know it in advance or can guess the denominator or part of it.



In your case, 1/Ans ΔFRAC



Returns: 6561



Which means that your number is the reciprocal of 6561 / 1



So it's 1 / 6561, like you said.

Answer 4

have the long decimal number out on the screen then go to MATH and select fraction. Then >FRAC will appear on the screen and you just click ENTER and it will give you the number in fraction form