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can however be made for the computer to do it directly. 'Long
multiplication' is extremely simple in the binary scale. For example,
multiply 11010 by 101:
11010
00000
11010
10000010
In practice one would not write down the second row, or any row
corresponding to 0 in the multiplier. As we see, the essential
processes are shifting the whole multiplicand successively to the left
and adding all the results. Means for doing both these things will
appear in the next section.
There are several possible electronic methods of subtracting,
corresponding to methods people use. In one, we replace each digit
of the number to be subtracted by its nine ...