The Expression number, also called the Destiny number, is derived from the full birth name, every letter of the name as first given, converted to a digit by the Pythagorean chart that assigns A to 1 through I to 9 and then repeats, and summed and reduced. Where the Life Path from the birth date describes the ground of the life, the Expression from the name is read as the natural talents, abilities and the goal the person is equipped to work toward, the fullest outward development of the self. Because it depends on the exact spelling of the name in the Latin alphabet, the number it yields is a property of modern orthography, and the system works in no other script, a point worth keeping in view when it is described as ancient. The whole apparatus is the American numerology of around 1900, the Balliett and Jordan system conventionally but inaccurately called Pythagorean.
Cheiro's 1926 Book of Numbers and Florence Campbell's 1931 Your Days Are Numbered both treated the full-name total under one name or another as the central figure of the chart, alongside the birth-date Life Path; Walter Burkert's study of the Pythagorean tradition is the standard demonstration that the letter-value chart underlying it, like the rest of the system, was assembled in the United States after 1900 and carries no descent from Pythagoras or from the ancient arithmological writers who wrote in his name.