Difference 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 larger quantity.

I know that I am four inches taller than my younger brother. If he is 41 inches tall, how tall am I?

number model:
41 + 4 = ___

Quantity

Quantity	Difference
41	4

It is equally important for students to learn how to solve comparison problems that ask for the smaller quantity.

For example:

I am 45 inches tall. I am 4 inches taller than my younger brother. How tall is my younger brother?

number models:
45 – 4 = ___
___ + 4 = 45

Quantity

Quantity	Difference
?	4

June 5, 2006