Lesson 1: Understand Volume
Videos:
Volume
https://www.youtube.com/watch?v=RxkRlIAucMk
https://www.youtube.com/watch?v=E8tuMaDxgJM
https://www.youtube.com/watch?v=LZxXUb9iAZc
https://www.khanacademy.org/math/basic-geo/basic-geo-volume-sa/volume-rect-prism/v/volume-of-a-rectangular-prism-or-box-examples
Games:
https://sg.mathgames.com/skill/5.93-volume-of-cubes-and-rectangular-prisms
https://www.mathplayground.com/geoboard.html