Subtraction is a much more complex operation to understand, because it can be used to solve problems involving three different situations. Whereas addition is the joining of two or more quantities, subtraction could be removal, comparison or finding a missing piece.
This is a single lesson where students learn about the three types of subtraction problems: removal (also known as "take away"), comparison ("the difference") and "find a missing piece (also known as "missing addend.") There are two activities: in the first one, students sort out 12 different word problems and place them in the type of subtraction problem it represents (there is also one addition problem thrown in to throw them off.....) After classifying the subtraction problems into three groups, they paste them onto a table.
The second activity is to write examples of these types of word problems to share with others. They also have to write an addition problem, so that they understand the difference.
This is the first of many materials that will feature that special character, Mr. Bagot!