If children often do their homework carelessly, no matter how many times they say it. Is it advisable to punish him for copying dozens of times? What are the advantages and disadvantages?

No, you'd better be patient and teach well. A drop of water can wear away a stone. He'll be fine, children. Why don't you enlighten him, listen to his own opinion and let him know? Punishment is unwise, it will make him rebel, and then he will be in trouble. Teach children for a long time and don't worry. You should pay more attention to him and make him moved, so the effect will be better. You try.