# Decimal to fraction?

I did .1/8, and the output was 0.0125000000. Is there a way to get it to display as 1/80.

Decimal to fraction?

I did .1/8, and the output was 0.0125000000. Is there a way to get it to display as 1/80.

add a comment

3

There are at least three ways to recover a rational from one of its numerical approximations:

```
sage: a = .1/8
sage: a.simplest_rational()
1/80
sage: a.nearby_rational(0.0001)
1/80
sage: a.exact_rational()
3602879701896397/288230376151711744
```

You can have a look to their respective documentations to see the differences. And you should understand that the floating point number `a`

is not equal to 1/80 but to 3602879701896397/288230376151711744 !

1

0

I've posted an alternate answer to the question at the link above. The basic answer: I ran across another way that's posted here where the author, John D Cook mentions the `nsimplify`

command in SymPy (which you can can access in Sage). Here's `nsimplify`

in action with your example

nsimplify is much more subtle and does not always return a rational as with nsimplify(3.2352)

Please start posting anonymously - your entry will be published after you log in or create a new account.

Asked: ** 2013-09-15 12:29:57 +0200 **

Seen: **1,374 times**

Last updated: **Sep 15 '13**

Get a matrix to display answers as decimals/floats, not fraction?

Display decimal as a fraction?

how to get output in a mixed fraction?

latex(-(x-1)/(x+1)) still broken

Changing number of decimal digits displayed in output

Using comma as a decimal mark with SageTeX

How to Rationalize the Denominator of a Fraction ?

partial fraction decomposition function for multivariate rational expressions

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.