Is it wrong for me to keep the left over grant money?

My dad paid for my classes and books. Financial aid came in (grants) and it seems to cover my tuition for me. I plan to give my dad the total amount of money he paid for. I seem to have a few hundred dollars left over though. Is it okay if I keep it or do I have to give it to my dad?
My brother keeps his left over money instead of giving it to my dad. My dad doesn’t say anything. But a year ago when I received a check my dad yelled at me to give it to him lol.