How Many Are Left?

To help novice mathematicians understand subtraction concepts, offer them visual representations of the operation. Here, they look at sets of circles. For each of the 16 sets there is a given number they are to cross out, writing how many are left in a box. They cross out one, two, three, four, and five circles, and all the totals are single-digit. By counting before and after they cross out the circles, learners are able to see the process in action. Do this with tangible objects, too!