Use $3.20 as average spend per beverage.

Use 68 as retirement age.

1. The number of purchased beverage I consume each day (1):
2. Amount (p) I spend per day on these beverages (2) = input from (1) above x p:

If you do not know how much you spend per beverage, use $3.20/beverage

3. The number of purchased beverage I consume each weekend (3):
4. Amount I spend each weekend on these beverages (4):

Average annual spending on beverage, in $; this is your C (5) =(2) x250 + (4)x50

Why only 50 weeks and not 52?

Because I am assuming that you all will take at least two weeks of vacation a year to avoid getting burnt out and you can indulge on a few costly beverages while on vacation.

5. Subtract your current age from the time you plan on retiring; this is your t (5), in years :

If you do not know when you plan to retire, please use 68:

Present Value (PV) of a t period annuity (We will see how and why later but lets not get stressed about it, for your class, its less relevant):

PV=Cr-Cr(1+r)t

Or,

PV=C1r-1r(1+r)t=Cr1-1(1+r)t

Using the discount rate .01, calculate the PV of your beverage consumption over your productive lifetime, in $: