Concept I dont know about

There are many times, that we don't know the basics of a topic, or lesson are; for example: Algebra, I don't know everything about it. The reason why i'm writing this is because, most of the time, while studying for the PSAT I don't know the foundation of a certain topic, and I have to then find what is related to algebra, and what is the foundation, this is also time consuming. I think that it would be really helpful if there was a tab under the lesson your doing that shows a menu of the basics, of the lesson that I need to learn, something I can access anytime I want, and repeatedly, not when the computer suggests me to do it. I think that would be a good addition do the website, as that can help the learning community, use time resourcefully, and not end up using it on having to find the basics, instead just press the link below, that opens a menu and shows what the foundation are for this lesson/topic, and what I can do to improve and learn the basics.