Sorting and Classifying
Sorting is the first act of data thinking. Before a student can make a graph, read data, or identify a pattern, they must be able to organize a set of objects by what they have in common. The power of sorting comes from the discovery that the same collection can be organized in many different ways — each revealing something different about the objects. Choosing the sorting rule, defending it, and changing it are all mathematical acts.
Sorting by a single attribute
An attribute is a property that objects can share: colour, shape, size, material, texture, function. Sorting by one attribute at a time keeps the task cognitively manageable and makes the rule clear. In Kindergarten, students choose their own attribute — this autonomy is important. There is no single 'right' way to sort a collection of buttons, leaves, or blocks.
Re-sorting: the same objects, different rules
The deepest learning in sorting happens when students re-sort. 'You sorted by colour. Now sort by shape — use the same objects.' This reveals that attributes are independent and that organization is a choice. Students who re-sort confidently understand that data can be viewed from multiple angles — a foundational statistical idea.
Sorting with natural and cultural materials
Sorting collections made of local natural materials — shells, leaves, stones, cedar bark pieces — connects mathematics to the land. First Peoples practices involve sorting and classifying plants, fish, berries, and materials in highly sophisticated ways, guided by ecological knowledge passed through generations. Inviting students to sort natural materials honours this connection and grounds the mathematics in place.