Inasmuch as the device is to be a computing machine there must be an arithmetic organ in it which can perform certain of the elementary arithmetic operations. There will be, therefore, a unit capable of adding, subtracting, multiplying and dividing. It will be seen in 6.6 below that it can also perform additional operations that occur quite frequently. The operations that the machine will view as elementary are clearly those which are wired into the machine. To illustrate, the operation of multiplication could be eliminated from the device as an elementary process if one were willing to view it as a properly ordered series of additions.
Similar remarks apply to division.
Lastly there must exist devices, the input and output organ, whereby the human operator and the machine can communicate with each other. This organ will be seen below in 4.5, where it is discussed, to constitute a secondary form of automatic memory. First remarks on the memory 2.1. The Macmillan Company, New York, 1963. Taken from report to U. S. Army Ordnance Department, 1946.