Interactive
Shodor Education Foundation

Shodor Interactivate: Lesson: Perimeter (Elementary)

For Teachers 3rd - 5th Standards
In this lesson students will practice finding the perimeter of regular and irregular shapes with right angles and the appropriate units for measuring perimeter.
Lesson Plan
Better Lesson

Better Lesson: Comparing Lengths

For Teachers 3rd
At the completion of this lesson, 3rd graders will understand how to compare the lengths of various objects. This lesson plan has detailed instructions that include pictures and videos.