Baseball Cards

Here is a resource that demonstrates growth and the initial state of an equation. In this case, your class will be looking at baseball collections. How many baseball cards did the collector start out with, and how many were added or subtracted each year? You could expand the resource by having your collectors come up with questions for the class. For example, which equation shows an increase of 100 baseball cards per year? You also could ask the class to think of other things that might have an initial state and grow each year.