You're right! I didn't look closely enough. You can indeed symbolize 72 with the method shown in the picture. Now that I finally get what viggity was saying

You're right! I didn't look closely enough. You can indeed symbolize 72 with the method shown in the picture. Now that I finally get what viggity was saying however, I think that what you can count to with two hands wasn't what was significant -- it was that a full, open hand was worth 60.