The Truth Behind Number Shapes

Have you ever thought why ........ 1 means "one", and 2 means "two"? The roman numerals are easy to understand but what was the logic behind the phonecian numbers?
It's the number of angles. If one writes the numbers down (see above) on a piece of paper in their older forms, one quickly sees why.
No 1 has one angle.
No 2 has two angles.
No 3 has three angles.
etc.

and "O" has no angles