The following are websites that the student can log into just like they do at school.  They use the same username and password as they would if they were logging into a school computer.  Your student's teacher has this information.

CLEVER gives access to Learning.com, CK 12-Foundation, Khan Academy, Discovery Education and MobyMax with one login

Renaissance Place AR quizzes

Mathseeds math program for K-2

Raz-Kids.com reading, writing & science (Classroom teacher has to have this set up for the class)