History of Hindu Mathematics: A Source Book v1.c7.s6.5

v1.c7.s6.5

**Forms and their Origin.** It cannot be satisfactorily explained why the number four, which was previously represented by four vertical lines came to be represented by a cross later on. The representation of the numbers five to eight follows the additive principle, with four as the base. This method of writing the numbers 4 to 8 is not met with in the early records of the Semites. We do not know how the number nine was written. It is very probable that it was written as [Figure:] , *i.e.*, 4+4+1 (reading from right to left, the order being the same as that of the script). The number 10 has an entirely new sign. The question why it was not written as [Figure:] , or why the base [Figure:] (4) was abandoned cannot be satisfactorily answered.