Any foundational math skill that should have been learned, but has not yet been learned is a gap in math. Let's look at an example. Students who reach grade 8 or higher who find math more difficult all of the sudden may have one or more math gaps. As frustration grows, they ask themselves: "Why has math become so difficult?" Maybe they are studying really hard, but it is just not enough. Since math concepts are cumulative, there may be some concepts that are missing from past
