Zero is a number used to signify nothingness, or an absence of quantity. Zero is also often used, in positional notation systems (such as the widely used Arabic numeral system), to allow for large numbers without symbols to represent orders of magnitude. Zero is the additive identity, which means that zero added to any number will yield that number. Although the Babylonians developed a positional notation system, they lacked a placeholder such as zero. The concept of zero arose independently in China, India, Mesoamerica and the Andes. Zero is not prime because it has an unlimited number of factors (anything times zero is zero), but zero is not composite either (zero cannot be expressed as the product of two primes because zero, which is not prime, must always be a factor). The mathematics of zero put forth by Brahmagupta, excluding one rule, are still in use today. The one rule that is not still in use is the statement that 0/0=0. The operation 0/0 is called an indeterminate form and has no clear mathematical value.