Prior to a lesson on re-sorting objects, present students with sorting mats containing various items, such as sorting bears or attribute blocks. As a group, students work to sort the objects: one day by size, the next day by color, and the third day by shape.

After students have completed these lessons, provide sorting mats containing a larger variety of objects. After every student has a sorting mat in front of them, ask students about ways they could group the objects. Use prompting to help students sort the objects. After they have successfully grouped the objects according to one attribute, ask students if they can think of another way the objects could be sorted. Continue in a similar fashion to sort by two attributes, such as color and size.

To extend this activity, model several groups of objects on a sorting mat and ask students to predict the rule used to group the objects. Repeat this with using the same objects and/or using different types of sorting materials.