Suppose the one-year nominal interest rate is 8%, and the expected inflation rate is 5%. What is the real interest rate?

I am not sure which one to use here:

Real rate = nominal rate - inflation -> r = 8 - 5 = 3%

or

Fisher equation (1+n) = (1+r)(1+i) -> r = (1.08/1.05) - 1 = 2.86%

I know these answers are close but can someone solve this problem, show their work, and explain why they chose the method they used?

Thanks