» What do I do if my students don’t have the pre-requisite knowledge needed to understand the new concept?

It is important that they have this – if we don’t meet students where they are at, we will not help them to really understand the math concepts. Sometimes you will need to go back several grade levels and re-teach very basic math concepts in order to be able to move forward. If you are in this situation, you can go to the concept courses, like “Decimals” and start at the beginning (or as far back as your diagnostic has indicated is needed). You may then be using both the grade courses and the concept courses.