Desmos Graphing Calculator:

 https://www.desmos.com/calculator

Edulastic: Interactive Formative Assessment for classroom or distant learning 

https://im.kendallhunt.com/

https://portal.achieve3000.com/index

https://www.khanacademy.org/math/algebra-home

https://www.khanacademy.org/math/geometry-home

https://certforschools.com/

https://newsela.com/