Finding grams of hydrogen gas using the ideal gas law

[n108]

If there are 6.25 L of Hydrogen gas at a pressure of 1.95 ATM and a temperature of 243 K, how many grams of hydrogen are there?

I know that the equation for the ideal gas law is:
pV = nRT
p = pressure
V = volume
n = number of moles
R = the gas constant, 0.0821 L atm mol-1 K-1
T = temperature

but I don't know how to fill in n, the number of moles.
this is my unfinished equation:
(1.95 atm) (6.25 L) = (n) (0.00821 atm mol-1 K-1) (243 K)

help, please!

 

[D H]

You know PV = nRT, and you are given P, V, R, and T. You even have R in the correct units. Just solve it!