How our partner would like to see it:
You can achieve this by using the format number function. Use the math function Format-Number in data mapper.
Below is sample syntax in which the Salary field is formated into required format that is 0000000000.00
format-number($Input_databasetesting/DB/sb4.eb22._._dbo._testingnew_/SALARY ,"0000000000.00" )
Here $Input_databasetesting/DB/sb4.eb22._._dbo._testingnew_/SALARY is XPath of source element.