This page is devoted to sharing resources for teaching online. If you have information you would like added, email Matt Chedister (email@example.com) or Mike Steele (firstname.lastname@example.org).
From AMTE National
AMTE National has made pages for resources. It can be accessed at: https://amte.net/resources/onlinestrategies or https://amte.net/content/instructional-resources-teaching-online-due-covid-19-virus
One page that might be of particular use is: Go To Math Task Sites. It is a list of math sites with valuable math tasks.
Also consider visiting AMTE Online Mathematical Teacher Education Task Force.