Attached is my video and two by the author. I am also attaching this SCREENCAST by the author, although it is a bit redundant, bacause you might get a better feel with the moving pictures. Don't forget the obligatory quiz (and make sure you've signed in to your sophia.org account).
Source: (C) 2016, Pearson
Source: (c) 2016, Pearson
Source: (c) 2016, Pearson