it's my life

Little Johnny was busy doing his homework. As his mother approached she heard:
"One and one, the son-of-a-bitch is two."
"Two and two, the son-of-a-bitch is four."
"Three and three... "
His mother interrupted, asking where he had learned this way of doing math. Little Johnny remarked that his teacher Ms. Margo taught him.
His mother was rather upset and told him to stop the homework. The next day she stormed into Little Johnny's classroom and confronted Ms. Margo. Little Johnny's mother told Ms. Margo about Little Johnny's different way of doing math, and his claims that Ms. Margo taught it that way to the class.
The teacher was flabbergasted. She said that she couldn't understand why Little Johnny had said what he did. Then suddenly, Ms Margo exclaimed, "Oh, I know, here in school we say, one and one, the sum-of-which is two."