I would like to format my numbers to always display 2 decimal places, rounding where applicable.
Examples:
number display
------ -------
1
If you're already using jQuery, you could look at using the jQuery Number Format plugin.
The plugin can return formatted numbers as a string, you can set decimal, and thousands separators, and you can choose the number of decimals to show.
$.number( 123, 2 ); // Returns '123.00'
You can also get jQuery Number Format from GitHub.