Have you ever thought why........? 1 means "one", and 2 means "two"?
The roman numerals are easy to understand but what was behind the Phoenician numbers? It's all about angles!
It's the number of angles.
If one writes the numbers down (see below) on a piece of paper in their older forms, one quickly sees why.
I have marked the angles with "o"s.
No 1 has one angle. No 2 has two angles. No 3 has three angles. Etc. and "O" has no angles
Interesting, isn't it?