We are now entering the last phase of the progression of working on our addition and subtraction math facts. This final stage includes working on subtraction from teen numbers, which tends to be the biggest weakness among our upper elementary and middle school students. Within the context of division of multi-digit numbers, students can be seen counting back a math fact using their fingers because they never developed efficient strategies for these math facts. It is particularly imperative, then, that we give these strategies plenty of instructional time so that students are not held up within work on complex math computations by the basic math facts.