Students mastering skills in math

I'm a math teacher. I need a program or a site where my students can start with a set of questions for level 1. If they pass this level the system will automatically assign level 2-type questions. Similarly, if students pass Level level 2, the system will automatically provide level 3. After level 3 the system will assign the next section where students receive the same process as levels 1,2 and 3. I will provide, or I can upload the bank of questions. I need a system that monitors their progress. Thanks