Several of the economics functions compute the
simple time value of money functions used in engineering economics
or investment analysis courses. These can be easily used outside
the data structures created by the add-in. For example the
function E_FP(interest, period) has two parameters, the interest
rate and period, and computes the future value of a present
amount. In textbooks, the function is often represented as
(F/P, i, n). Excel has a built-in functions to compute this
value, but we provide these functions to more closely agree
with the notation of engineering economics texts. Similar
functions are E_AF, E_AG, E_AP, E_FA, E_FP, E_PA, E_PF, E_PG,
E_PGeo. Generally A stands for a uniform series, G a gradient
series, P a present value, F a future value, and Geo a geometric
series. These functions can all be copied from the Economics
add-in *Function* module and pasted into the user's
VBA module.

Other functions have more complex arguments
and may call other functions and subroutines. The functions
prefixed with NPW compute the net present worth of a cash
flow with and without inflation and with and without the effects
of taxes. They are more tied to the data structures of the
Economics add-in.