How Old?

This activity uses the knowledge that the students have developed in Shaker Makers on the previous page by asking them to distinguish between “teen” and “ty” numbers.
The students need to have had various learning experiences where written numbers are presented alongside a concrete model of that number, as shown in Shaker Makers. Beans or counters can be grouped in tens in opaque film canisters; ice-block sticks can be bundled into tens; multilink cubes can be joined into stacks of 10. With all of these materials, the students create the unit of 10 by grouping 10 ones and can also easily break the 10 into ones again.
The hundreds board can be a useful reference point for the students to check how a number looks. However, students who are still confused about “teen” and “ty” numbers should do more activities that involve making numbers with concrete materials (such as those in Shaker Makers) before moving on to the more abstract work on this page.
 

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