What you you think of beating up a rude kid
Really? What makes you think this kid deserve to get beat up?
I just want to beat him
This kid must have really upset you, which is understandable, however you shouldn't hurt someone who's so much younger than you. If anyone sees you then you could get in serious trouble.
He's stupid and I hate kids like him.
I understand you're really upset with this kid right now. You really should try to understand that causing any harm to him could put you in a really bad situation. It's not worth it in the end to cause harm to this child.