Is mobymax.com Safe?

MobyMax is a site where kids can do different subjects' practice. The more they practice, the more game time they get. Every 50 questions they answer gives kids a badge where they can read about something and learn things. Also, the daily challenge gives you a badge or game time. The weekly challenge, you have to do it all in a row, 5 minutes a day gives you a grand prize when you finish, and it is a picture of something, kind of like a puzzle! Teachers can assign things on MobyMax! MobyMax is fun, and totally educational. At the beginning of each subject, kids take a pre test to see where they need to improve.