In the past few days I've run across LearnZillion while looking for videos to use in class. At my school, youtube is blocked and if you want a video from there, you have to put in a request at least a week early to have the block removed so you can download the video for class. I used two different videos from this place today.
The first video was on percent of increase. It was short but very much to a point and provided a way for students to figure out the rate of increase or decrease while using the same formula. I had my students watch the video and then we started working problems. By the 5th problem, most of the students were able to work independently.
The second video was on complementary and supplementary angles. Again, the video was short but full of information and quite clear. Even my students who struggled, learned from the video.
When I went to the site I discovered they have both lesson plans and video for various grades, including high school math. Although the material is free for registered users, they do have a premium subscription for districts.
I plan to explore the lesson plans to see how well cover the material I want covered.