"2+5, the son of a b**ch is 7"
"3+6, the son of a b**ch is 9"
His mother heard this & asked, " Henry ! What is this nonsense you are doing?"
"Oh Mom. Don't disturb. I am doing my maths homework"
Mom: "Is this how your teacher taught you?"
"Yes mom "
Infuriated mother picked up her cell phone and called the teacher:
"Are you teaching maths to children by saying... 2+2, the son of a b**ch is 4?"
There was silence for a moment
Then the teacher started laughing :
"What I taught them was... 2+2 THE SUM OF WHICH IS 4."