It blew my mind that I didn't have to buy the lower level skills prior to learning the higher level skills in the same row.
For example, you can buy the tier 1 defense, then tier 2 magic, then tier 3 attack.
basically, if your numbers can be divided into a low number, your shape will be finished quickly.
2, 4, and 6 for example go into 12, this shape finishes really fast.
3.141592653, 7, and 6.666666 however will connect with its starting point a very long time from now.