I made this with a lot of heart, and every purchase helps me keep creating.
If you like what I do or just want to support independent makers, check it out:
http://amazon.com/gp/product/B093D22DGN
Thank you for being here—it really means a lot.
complete explanation for volume of a pyramid here:
coming soon!
Sum of integers squared video link:
https://www.youtube.com/watch?v=229csazhybg