A fifth grade teacher is told she must teach sex education
to her class.  She decides to use a math technique to teach
the subject, and thinks flash cards will work well.

The next day in class, she holds up the first flash card, a
picture of a breast, and asked "does anyone know what this is?"

Little Suzie responds - "I know, I know!  It's a picture of
a breast and my mommy has two of them!"

The teacher says "very good Suzie, you get a star for the
exercise".

The teacher grabs the next card and holds it up.  It's a
picture of a penis.  She asks "Does anyone know what this is?"
and little Johnny says "I know, I know!! It a penis and my
daddy has two of them!!!"

The teacher says "well Johnny, It is a penis but your daddy
can't have two of them."

Johnny says "yes he does, he's got a little one he pees out
of and a great big one he brushes mommy's teeth with!"