1

Every letter of the full birth name goes into this sum, so a middle name counts along with the first name and the surname. Take Sara Lang: Sara adds to 12 and reduces to 3, Lang adds to 16 and reduces to 7, and 3 plus 7 makes 10, which reduces to 1. The calculator works part by part and also shows the all-at-once total, since the two routes can disagree.

The word itself has a history. Cheasley in 1916 is the earliest book in these sources to use Expression for the whole-name sum, and Wilson in 1922 writes Expression or Destiny Number. Walton in 1914 calls it the Destiny number outright.

Cheasley's entry for 1 lists self-reliance, reasoning and a pioneer's faculties, and Taylor in 1926 gives the letters A, J and S initiative and daring. Walton is harder on it and calls 1 petulant and self-centered. Modern popular books keep the pioneer and read an Expression of 1 as ability shown through starting things alone.