I’m doing my homework

A little boy was doing maths homework, saying to himself, 2+5 the son of bitch is 7,
3+6 the son of bitch is 9
His mother heared this & asked “what r u doing?”
Boy, “doing my maths’ homework”.
Mom: & this is how ur teacher taught u?

Boy: “Yes”

Infurriated mother called the teacher: R u teaching maths to children by saying 2+2, the son of bitch is 4?

Teachr started laughing & answerd: “what I taught them was, 2+2 THE SUM OF WHICH IS 4…