Wiy ER T s QeI R A S AN AR SistahaL T TR 10 THE FASCINATION OF NUMBERS system based upon groups of twenty (instead of groups of ten) presumably required the use of the calculator’s toes as well as of his fingers, and we may consider ourselves fortunate that this physical process is no longer required of us! The Roman system of numbering suggests that at one time counting was effected on one hand only, for this system divided numbers into groups of five. If we study the first five Roman numbers, it is not difficult to relate them to pictures of the human hand. If the right hand is held face upwards one can easily visualize each of the fingers as a vertical stroke of a Roman number, whilst the angle at which the thumb departs from the vertical provides the form of the letter V, the Roman symbol for the number &. But whatever the size of the actual groups used, it is this fundamental system of grouping which enables us to .deal adequately with the larger numbers. Without the aid of the grouping system each different number would require an entirely different figurate name instead of| as at present, having a composite name derived from the groups of which it is composed. In other words, a totally different symbol would be required for each different number. Every number is made up from a group of digits and it is the relative positioning of those digits—each to the other— which gives the identity of that number. Just as the order of musical notes decides the nature of a piece of music, so does the order and placing of digits decide the nature of a number. If the order of the digits is changed then an entirely different number will emerge. This is because a digit has a different meaning in different positions—a fact which is essential in a system which uses only ten symbols and yet succeeds in using those symbols to express any conceivable number. Each number is built up to a definite pattern so that a sequence of digits in one particular order can represent only one particular number. The number 1234, for instance, is made up of one thou-