It has many systems and traditions and beliefs. Numerology and numerological divination by systems such as isopsephy were popular among early mathematicians, such as Pythagoras, but are no longer considered part of mathematics and are regarded as pseudomathematics by modern scientists.
Today, numerology is often associated with the paranormal, alongside astrology and similar divinatory arts.
The term numerologist can also be used for those who place excess faith in numerical patterns, even if those people don't practice traditional numerology.
Examples include the Abjad numerals in Arabic, the Hebrew numerals, Armenian numerals, and Greek numerals. The practice within Jewish tradition of assigning mystical meaning to words based on their numerical values, and on connections between words of equal value, is known as gematria.
1= a, j, s; 2= b, k, t; 3= c, l, u; 4= d, m, v; 5= e, n, w; 6= f, o, x; 7= g, p, y; 8= h, q, z; 9= i, r
...and are then summed.
3,489 → 3 + 4 + 8 + 9 = 24 → 2 + 4 = 6
Hello → 8 + 5 + 3 + 3 + 6 = 25 → 2 + 5 = 7
A quicker way to arrive at a single-digit summation (the digital root) is simply to take the value modulo 9, substituting a 0 result with 9 itself.