Geogebra (the website will open in a new tab) Digital math tools, calculators, and activities.
Mathigon (the website will open in a new tab) Interactive and engaging math lessons and clickable activities on topics such as graph theory, prime numbers, triangles, and map coloring.
New York Times: What's Going On in this Graph (the website will open in a new tab) Every week students have the opportunity to view a new graph, answer questions about it, and participate in a discussion with the American Statistical Association.
US Census Bureau Math Worksheets (the website will open in a new tab) Math activities, provided by the US Census Bureau, to be used along with census data. Each activity has links to downloadable teacher and student versions.