Decreasing Variation

Transforming Teacher Learning to Student Learning
Sue Lampkin - Mountain View, California - Kenneth E. Slater Elementary School

Applying math knowledge to teaching practice

Looking closely at student learning

Faculty learning in collaboration

Here is a basic problem to solve for the outcome of a "change-to-less" situation.

A bus leaves school with 35 children. At the first stop, 6 children get off. How many children are left on the bus?

number model: 35 – 6 = ___

35		?
start	change	end

It is equally important for students to learn how to solve to determine the change when the outcome is known.

For example:

A bus leaves school with 35 children. After the first stop, there are 29 children on the bus. How many children got off the bus?

number models:
35 – 29 = ___
35 – ___ = 29
or perhaps 29 + ___ = 35

35		29
start	change	end