One way:

=FV(5%/12, 12*40, -50, -250)

In article ,
"Msnews.Microsoft.Com" wrote:

Hi,
I need a formula for figuring out a retirement saving plan for my Grandson.
He wants to start by depositing $250.00 initial investment and adding
$50.00 per month for 40 years. If he earns 5.0% interest compounded monthly
how much will he have in 40 years? Any help with this formula will be
greatly appreciated. Thanks. Starlin