I'm Tired Mommy!

My son has a homework. When we got home, I told him to do his homework right away. He needs to write the numbers 1-10 on a sheet of paper his teacher gave him. He just wrote until the number 5 and after that he told me and my husband that he's tired.

I told him that he can rest when he is done with his homework but he kept telling me he cannot he do it anymore. My husband just told me to let him go because if he is really tired then he cannot concentrate. So, I told him to rest and no tv. I will just let him finish it before he go to school tomorrow, I hope he will be in a good mood when he wakes up.