If you need a specific number of decimals, you better use FormatDecimal(number, N), because str() will convert 2.40 to "2.4", omitting the last 0
With FormatDecimal(2.4, 2) you will get a string with 2 digits for the decimals "2.40"
Likewise, FormatDecimal(2.41, 3) will return "2.410", etc.