To compare growth rates and changes in rates qualitatively, again using the plant strip displays.

These lessons provide opportunities to compare plants and their patterns of growth (for example, times of faster and slower growth). The plant strip displays are shown together or overlaid to allow children to answer questions such as:

Is the plant growing faster now than at the beginning of its life cycle?

Did this plant grow taller than the other plant?

In whole class discussion, students interpreted the paper strip displays for each plant. By referring to the differences in lengths of paper strip, they determined which plants grew faster at the beginning of the life cycle vs. later. They could readily identify times when plants were growing very fast, or when growth had stopped.

By overlaying the displays, they found the plant that was the tallest at the end of the life cycle. This claim was also supported by their calculations of overall growth for each plant (that is, the difference between initial and final heights).