Activity
Texas Instruments

Texas Instruments: Design a Quilt

For Teachers Pre-K - 1st
Students learn to use pattern blocks to build a two dimensional design, and use the calculator to determine the value of the design.
eBook
Mathigon

Mathigon: Geometry: Circle and Pi: Conic Sections

For Students 9th - 10th
The circle is one of four different shapes which can be created using "slices" through a cone, a 3-dimensional solid that has a circular base joined to a single point (called the vertex) by a curved side. If you tilt a cone, you get an...