Pythagorean Numerology — Definition
Pythagorean numerology takes its name from the Greek philosopher Pythagoras, though the modern system is a 20th-century reconstruction rather than a direct lineage. Letters are assigned values 1 through 9 in alphabetical order (A=1, B=2 … I=9, J=1, and so on). Calculations are then reduced to a single digit, except when a master number appears. It is the dominant system in English-language numerology because of its simplicity and consistency.
Example
In Pythagorean numerology, the name "Anna" reduces as 1 + 5 + 5 + 1 = 12 → 1 + 2 = 3.