The proper way to do this is using something like TryParse() and ToString() and to handle the case of failing to parse the string as a number and maybe even spe

The proper way to do this is using something like TryParse() and ToString() and to handle the case of failing to parse the string as a number and maybe even specifying the locale for both operations. If you are absolutely sure that parsing can not fail you can use Parse() and omit the error handling.