The following functions are available in emacs calc and python’s numpy.

Suppose you’re getting the following payments

tv

If we were take into account that the value of these payments, assuming you put them in the bank right away and get interest on them of 5%, then the future value would be as seen the below chart

fv

You can calculate this sum as 2000+2000*1.05+2000*1.05^2+2000*1.05^3

Or more easily in calc, this would be 5% RET 4 RET 2000 RET b F

pv

It can be seen that the present value of these payments is pv*1.05^4=fv

In calc, this would be 5% RET 4 RET 2000 RET b P