Adding specific classes to a student account

My child has two different accounts for some reason, one has just his name .. the other his email. On the account with just his name listed, I can select and add specific classes out of each subject with ease. He can not see the classes listed though. On the email account, he can see everything, but i can only add a whole course at a time and this is too many assignments for one day. I dont want to add whole assignments at a time. I need to be able to select certain parts for multiple subjects daily. Any help would be very much appreciated!