Calculator inputs
There are five variables in a bond valuation problem. Using a financial calculator requires that you type in the four known elements (N, PMT, I, and FV) and solve for the one unknown, the present value (PV).
Computational details
The value a bond today is the sum of the present value of the interest payments (valued as an ordinary annuity) and the present value of the face value (discounted as a lump-sum):
PV = [ S CFt/(1 + i)t] + [FV / (1 + i)t]