National Security Agency
Awesome Area - Geometry and Measurement
Break out those math manipulatives, it's time to teach about area! Capturing the engagement of young mathematicians, this three-lesson series supports children with learning how to measure the area of squares, rectangles, and other...
Shodor Education Foundation
Triangle Area
While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...
Curated OER
Sphere Dressing
Geometric design makes a fashion statement! Challenge learners to design a hat to fit a Styrofoam model. Specifications are clear and pupils use concepts related to three-dimensional objects including volume of irregular shapes and...
Curated OER
Exploring Number and Operation in Secondary Mathematics
Young geometers need a clear understanding of perimeter, volume, and area. This lesson provides a worksheet to help small groups of learners to calculate various measurements of objects and choose the proper units for measurement. It...
Illustrative Mathematics
How Many Leaves on a Tree? (Version 2)
A second attack at figuring out the number of leaves on a tree, this activity makes both an excellent follow-up to version 1 and a stand-alone activity. Learners practice setting parameters and deciding acceptable estimate precision, and...
Teach Engineering
Determining Densities
Don't be dense—use a robust resource. The second installment of a five-part Floaters and Sinkers unit has learners determine the densities of several objects. As part of the activity, they learn the displacement method for finding...
Teach Engineering
Density Column Lab - Part 2
Groups suspend objects within layers of liquids to determine the densities of different liquids and compare them to the densities of objects calculated in Part 1. The groups then carefully test their calculations by layering the liquids...