Useful math sites:

1.   Khan Academy

https://www.khanacademy.org/

Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, history, art history, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. 

2.   Learn Zillion

https://learnzillion.com/p/

This site has math and ELA curriculum, instructional videos, online assessments, teaching guidance and custom manipulatives. You will have to set up a free account to get started.

3.  Scholastic’s Study Jams

http://studyjams.scholastic.com/studyjams/

Lesson on this site come in a variety of forms.  They have step-by-step lessons, quizzes, videos, and even karaoke.