Screencastify (or screencast-o-matic if not on a chromebook)- Allow the recording of up to 10 minutes of either a tab in a browser or using a webcam. I just made sure I downloaded the video to google drive and shared it to free up my 10 minutes.
Daum Equation Editor - This is a web based equation editor where I could type in the problem end explicitly work through how I solved the problem.
Webcam - Like a webcam, many document cameras can hook up to a computer with a USB cable. This will turn the document camera into a high resolution camera. I often used this to record my hand writing out the solution to a problem on a piece of paper, just like you would do it on the board. While doing this, you can also project the image that you are recording.
WeVideo - If I wanted to get fancy. I could edit the video. As I tried to keep these to quick videos, I rarely used this tool.
Tell the Class to be Quiet and hold their Questions.
As I would go over the problems, I would always save one problem to screencast. When I got to this problem, I would tell the students to be quiet and that I would be turning this into a video. I would record the video and audio of me solving the problem, then post it online for students to see. Upon completion I would turn off the recording and ask if there were more questions.
Get it Done Before Class.
Prior to class I would do the same thing and I would post them to my class webpage. As students entered the room, I would check their homework and then tell them where to find the videos in case they had questions.