Data Conversion/Cell Formatting

I'm having a little trouble figuring out how to do some conversions. For instance, I would like to know how to convert a decimal number like this:
1.800

which is a ratio of 1.800:1 to display like this:
9:5

So, when the 1st value changes to something like this:
1.778

It would be displayed like this:
16:9

Likewise, a ratio of 1.333:1 would be displayed as 4:3.

I also don't want it display in Time format as Excel has a habit of converting values with colons to time format.