My brain is standing completely still on this. I'm sure I've known this in the past. The difference between the number:
is obviously that the first number number is a "full" number. There is no fraction of a number that requires that the number be written with a period symbol and more numbers describing the fraction.
What is a number called when it can be written without a period, and what is it called otherwise? Also, what are the numbers behind the period symbol called? (So really this is a request for three words, not one. I hope that flies.)