Most who have studied this puzzling passage connect the calculation with the practice known as gematria where different letters of an alphabet are assigned different sequential numeric values so that words then derive a value equal to the sum of the values associated with their individual characters.
With the late Jews and the Greeks the letters of the alphabet were used to denote numbers; a name then could be given enigmatically in the sum of the numbers denoted by its several letters. Thus in Gen. Gen. 14:14 the number 318 was taken by the rabbis to denote Eliezer; the numbers denoted by the respective letters of that name added together form this sum. The Christian Sibylline I. 324 ff. uses 888 for the name ʼΙησοῦς [Iēsous] , Jesus.1