Action Subtraction is a differentiated “case” that promotes independent problem-solving in the area of subtraction. This is an activity to be used after students have had plenty of guided practice with solving subtraction problems in different ways (using manipulatives, number lines, hundred’s charts, counting backwards, drawing pictures, etc.)
The premise of this activity is that students will solve a range of increasingly difficult subtraction problems…left for them at Math Genius Headquarters by the evil Dr. Tricky McTrickster. For each problem they solve, they will have to use at least two different strategies to reach their answer. At the end, after they have solved all four pages of “the case”, they will have to determine which strategies they found most helpful in a quick self-assessment.
There are three levels of this activity. The first four pages are subtraction problems within 10 (problems are shown vertically and horizontally). The next four pages of problems are problems within 20. The last four pages include some mixed practice and multi-step, mixed practice problems.