In mathematics, the natural numbers are the numbers 1, 2, 3, etc., possibly including 0 as well.^{[under discussion]} Some definitions, including the standard ISO 80000-2, begin the natural numbers with 0, corresponding to the non-negative integers 0, 1, 2, 3, ..., whereas others start with 1, corresponding to the positive integers 1, 2, 3, ... Texts that exclude zero from the natural numbers sometimes refer to the natural numbers together with zero as the whole numbers, while in other writings, that term is used instead for the integers. In common language, particularly in primary school education, natural numbers may be called counting numbers to intuitively exclude the negative integers and zero, and also to contrast the discreteness of counting to the continuity of measurement—a hallmark characteristic of real numbers.

गणित में 1,2,3,... इत्यादि संख्याओं को प्राकृतिक संख्याएँ कहते हैं। ये संख्याएँ वस्तुओं को गिनने अथवा क्रम में रखने के लिए प्रयुक्त होती हैं।