Java has only one way of storing real numbers (float or double), which follows the IEEE 754 specification. So "500000000" and "5.0e8" are not different numbers, but simply different ways of displaying (formatting) the same number.
If you don't like how a number is displayed, you can use the "java.text.DecimalFormat" class to control it. Look at this example:
When run, it displays:
Float 1: 8.0E7
Float 2: 8.0E7
Float 1: 80000000
Float 2: 80000000
Float 1: 80000000.0000000000
Float 2: 80000000.0000000000
So you can see that both "80000000F" and "8.0e7F" are the same number as far as Java is concerned. If you don't like how it get printed out, change it.