Numerology uses numbers as a key to human behaviour. Numerology is not a complete science it is just s branch of the predictive sciences. For a numerologist there are only 9 numbers from which all calculations of the material world are made.

Sun =1
Moon=2
Jupiter =3
Rahu =4
Mercury =5
Venus =6
Ketu =7
Saturn =8
Mars =9

All numbers beyond 9 are repetitions. The number 10 is not a whole number, it is simply a 1 with a 0 etc.

In Vedic numerology we use 3 basic concepts;

1) Psychic no= representing self image
2) Destiny no= pertaining to karma and how others perceive you
3) Name no= Social/ professional life.
Together these three numbers reveal info about your temperament, intelligence, sexuality, finances and health.