A natural quantity is actually a attribute of a group, applied to describe its dimensions (how it is many) and distinguish it from other collections. The natural figures variety a set, generally symbolized to be a Daring N or blackboard bold ⁠ N displaystyle mathbb N purchase in, fill up, https://share.evernote.com/note/a8fd1cb2-5733-5366-f5df-7a36578ae666