Many everyday events give rise to a need for quantitative thinking, thus leading to the creation of numbers and number relations in living experience. Such development of number in the normal spheres of human activity is one of the fundamental modes of human thought, and early consideration of this initial number work may be confined to verbal form. At this stage, situations requiring number thought can be discussed as they arise, and two consecutive situations often have no more in common than the use of number itself. It is this realisation which enables number-learning to take place. Increasing awareness of number and number-relations brings greater complexity, and it is then that the notation of number is needed. This notation has to be learned in relation to the ideas represented, and there are two major forms :
(i) The figures 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and the notion of place position to represent other numbers.
(ii) The use of a standard measure to facilitate comparisons between certain similar quantities such as length and weight.