Categorizing Objects

Logic and critical thinking skills are essential for math -- so we tend to teach a lot of basic thinking skills in math (although, they are not exclusively math skills).

One of those thinking tasks is the work of categorizing objects: what belongs? What does not belong?

In thinking about what belongs, students need to learn to think about the different qualities of objects, some of these qualities are related to math:

• How long is the object?
• How wide is the object?
• How many sides does the object have?
• How many corners does the object have?
• Are the object's sides round or straight?

Other qualities have less to do with math:

• What color is the object?
• What does the object represent?
• What texture is the object?

But the process of discriminating between objects that are the same or different is critical for mathematical thinking (think about categorizing triangles by angles or sides or about combining like terms in algebra).

For young students, start with general patterns and groupings: which objects are the same?  Which are different? Why? Push students to verbalize the qualities that make objects the same or different.