I learned something new today about an Oracle function I have been using for almost 20 years... Never a dull moment :-)

If you use to_char like this: to_char(1, '990D99') you get "1.00", with some leading spaces.
However if you use this: to_char(1, 'fm990D99') you get "1.".

The Oracle documentation on Format Models states "FM: Fill Mode. Oracle uses trailing blank characters and leading zeroes to fill format elements to a constant width. [...] The FM modifier suppresses the above padding in the return value of the TO_CHAR function.".
I found no mention of removing trailing zeros, so still not sure why FM creates this difference.

In the "FM and zeros" example above, the "fm990D99" formatting of 1 results in "1.".
To remove the decimal character from that result, you could use a dirty "nls_numeric_characters" trick - see the code below. Not recommended, but fun :-)