Source: sophia.org YouTube Channel
Then you can add text here to help explain the equation.
Source: Author Created
Source: Author Created
This file was created and downloaded from Soundcloud.com
Source: Author Created
No sound. I used Sophia to beat the filter when YouTube was blocked. You can make your own and export them as an mp4 or download them from YouTube using application found here. http://www.digitaltrends.com/computing/how-to-download-youtube-videos/
Source: Author Created
Source: Author Created
Source: Author Created