So in our previous example where X was 5678 and Y was 1234 we would have A being equal to 56, the first two digits of the four and X and D would be the other two digits and similarly for C and D in a D composition of Y. So now on just purely mechanical way we can expand the product of X times Y in terms of misrepresentation in terms of these smaller numbers A, B, C and D. So X times Y by representation, is just the same thing as 10N over two times A+B times quantity ten to the N over two, C+D. 