The son of a bitch

Henry was doing maths homework, saying to himself...

"2+5, the son of a bitch is 7"

"3+6, the son of a bitch 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 bitch 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."

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