you learn 95% of what you teach, even if you are teaching to an audience via video. So, to prep for the college Trig final this year, I handed students a 20 question Study Guide and taped a sheet of paper with a table numbered 1-20 to the classroom door.
I invited them to sign up to demo one of the questions on the Study Guide...with a partner, of course (to hold their phone). The students, now pros at explaining mathematical "how-to's" and "why's" eagerly volunteered to explain a problem (well, let's be real for a moment...these were seniors about to fly the coop so, I offered bonus points - something I rarely, if ever do - to everyone who actually spoke and demonstrated their mathematical prowess in the video). It was amazing to see how quickly the students volunteered to explain how to work a problem of their choosing!
The students uploaded their videos to You Tube (something else they learned this year) and then shared the link via a Google Form. I created a QR Code of their link using QRStuff and took a screenshot of the code (it also let's you save the image if you want).
I inserted the image into the corresponding square of a clean copy of the original table numbered 1 - 20.
The QR Code Table was shared with each of the students and updated regularly until all of the student videos were added. It has always been a dream of mine to be able to hand students a Study Guide and a sheet with links to relevant student-created videos to support their studies. So, this was my year!!! I really had students sitting in class wearing earphones and using a cell phone to scan QR codes to watch their friends explain math problems. It still makes me smile in July!