Why do my parents make me do my homework over the summer?

thats alot to do. i alsohave to do homework over the summer. its so we can keep everything we learned AND learn new stuff. but i use to have to do alot of it. i just told my mom that i didnt think itwas appropriate to have me doing soo much homework. she ended up taking back some of the homework and only gave me 4 sheets every other day.