So today my teacher went over birth control in Biology class.
She was telling us the failure rate for each method, and for one of them, she counted out how many people were in the class and then used that percentage to count off and make every fifth person or so stand up.
Those people were supposed to represent all the women who used that form of birth control and still got pregnant.
The funny part though was that every fifth person in the class just happened to be the honors-student type people, with the best grades, least likely to do that kind of thing, etc.
So really, worst example ever. :P