 In practice the last letter, "tav" (which has the value 400) is used in combination with itself and/or other letters from "qof" (100) onwards, to generate numbers from 500 and above.Alternatively, the 22-letter Hebrew numeral set is sometimes extended to 27 by using 5 "sofit" (final) forms of the Hebrew letters.By convention, the numbers 15 and 16 are represented as (9 + 6) and (9 + 7), respectively, in order to refrain from using the two-letter combinations (10 + 5) and (10 + 6), which are alternate written forms for the Name of God in everyday writing.