Fizz-Buzz is a classroom game. You start counting around the class but if your number has a five in it either as a digit OR a factor you say Fizz instead of the number. The same with sevens only you say Buzz this time. So the first kid says 'one'
Next kid says 'two'
and it continues 3, 4, Fizz, 6, Buzz, 8, 9,Fizz-Fizz('cos 2 5s are 10), 11, 12, 13, Buzz-Buzz, Fizz-Fizz-Fizz, 16, Buzz, 18, 19 and so on.

Bert.