# 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.

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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)

Asked: **
2013-09-15 05:29:57 -0500
**

Seen: **1,104 times**

Last updated: **Sep 15 '13**

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