Please tell me how to calculate NPV (Net Present value)

Please tell me how to calculate NPV (Net Present value)
I have to give to my owner calculations for the following - His investment 60,00,000 every year for 40years
Discount @10%. He is asking me to give Net Present value for the same.
19th January 2012 From India , Delhi

First Mention Cash Inflow for 40 years
than Find PV
PV = 1/(1+Discount Percent)^N
N= Number of Years
Then Multiply the Cash inflow of each year to Pv of each year
that will be discounted PV
Take total of discounted pv and minus it from original investment
if value comes in (+) approve the project otherwise not
5th March 2012 From India , Pune

on your calculator
enter 1/1.10 and press equal sign button for 40 times.
then press the GT button, you'll get 9.7790507
now multiply it with your principle amout i.e. 60,00,000
the net present value for this is 5,86,74,304.20/-
8th February 2013 From India, Delhi