The two most popular methods of numerology are Pythagorean and Chaldean.
Though each is a different system, with distinct differences, they both are in agreement on certain things.
Letters converted using nos. 1 to 9
Started about 600 BC
Sometimes called Modern Numerology
More popular because easier to use
Gives a more materialistic meaning
Uses full name given at birth
Conversion is done in sequence
Pythagoras a mathematician used it
All compound numbers reduce to single numbers.
Letters converted using nos. 1 to 8
Sometimes called Mystic Numerology
Harder to use than Pythagorean system
Gives an occult or mystical meaning
Uses name most known as
Shows the behind unscene forces
Conversion is out of sequence
Unknown who originally taught it
Predates the Pythagorean system
Birthday affects personality and health tendencies given at birth
The Single and Compound number are both important.