Nine Basic Numbers Were Once Used With No Zeroes. Zero took a long time to make an entry into our modern counting system. One of the reasons was the one time ubiquitous use of magic number squares in antiquity. Avoiding zero had a number of reasons. In the English language in particular, the term was avoided for quite a while. The first known English use of zero was in 1598.
Fibonacci (c. 1170–1250) introduced the decimal system to Europe using the term zephyrum. This became zefiro in Italian. It Venice it was contracted to zero.
So Why Only Nine Basic Numbers?
Number squares (a.k.a. magic squares) were the guiding light of the ancients. Our feature picture shows the prime number square. Seven were used. Each was a assigned to a different celestial body. They ranged in size from 3 x 3 to 9 x 9. One squared and two squared merely define the centers of these squares. Ten was synthetic as it fused any two opposite numbers on this square.
What is so significant about these magic squares? They teach the lesson of balance; each square balances in several ways. For example on the 3 x 3 any two opposite numbers equal ten. Any straight row of three numbers total 15. If something was wrong with the world, you might say it was out of balance.
The Five Platonic Solids are Another Nine Reason
The simplest and basic polygon was the tetrahedron. With four triangles, at 180° per triangle, it totaled 720°. The most complex was the dodecahedron. It had 12 pentagons around its core. It had the most angular degrees with 6480°. Divide the most complex figure by degree number by the simplest: 6480 ÷ 720 = 9. I explain how the 3 x 3 magic square stamps out the five solids in another post. For that reason ancients used 9 basic numbers.