How to see my fps on minecraft on my windows 8.1 laptop?

Whenever I try to do anything using the f keys it just does stuff like volume and brightness. How can I see my fps and make it so that doesn't happen when I use those keys? My minecraft is updated to 1.7.10.

Guest

I have a Windows 8.1 laptop, all you need to do is press down the FN key next to CTRL while pressing the F keys, not sure why. But there's a way you can change it so that it doesn't do the function and just presses the F keys, i can't remember though, hope this helps C

Scarlett