6. Design a circuit to add four 4-bit numbers as unsigned operands. 7. (a) Show the widths of the four CSA required to reduce six 32-bit unsigned binary numbers to two numbers (b) Repeat part (a), but this time assume that the six 32-bit unsigned numbers are the partial products of a 32x6 multiplication (i.e. they are not aligned at their LSB but shifted to the left by 0, 1, 2, 3, 4, and 5 bits).