10 is not a number, but more of a concept, or you could say it’s Nature’s way of organizing herself. The Pythagoreans considered there to be only 7 numbers in reality. Unity and duality, 1 and 2, were not considered numbers. Numbers began at three and ended at the most auspicious of all, NINE.
Ancient mathematical philosophers called NINE the “finishing post” and “that which brings completion”. – Michael Schneider – ‘A Beginner’s Guide to Constructing the Universe’
Ten is the combination of something with nothing. The one is borrowed from the Ennead with the addition of zero to organize all numbers with this built-in qualitative invariance in their expansion and contraction. In other words 432,000, the number of years in the Kali Yuga (a time cycle in the Vedic tradition) has the same meaning and symbolism as 43,200, the number of seconds on the face of a clock, and the Great Pyramid’s expansion factor in relation to Earth’s northern hemisphere.
The numbers may vary by the total amount zeros, but their qualitative expression remains the same no matter how big or small.
The process of reducing a number down to one digit is called many names and is common practice not only in numerology but also in mainstream science. The great geometric genius (alliteration aside) of the 20th Century, Buckminster Fuller, called this subset of math ‘integrated digits’ or ‘indig 9′. It is also recognized in computer science. They call it a ‘digital root’ or ‘digital sum’ or ‘quantum bit’. This process has also been called Kabbalistic reduction or Pythagorean addition. Some other names for this practice include: decimal parity, quantum numerology, theosophical addition, indig , integrated digit, indig 9, modulo nine arithmetic, number essence, reduced ordinal values, horizontal addition, and numeric reduction.
55 has a digital root of 1 because 5+5=10, and 1+0= 1
456 Kabbalistically reduces to 6, since 4+5+6= 15 , and 1+5= 6