It has to be a stuck key. Wiggle each key as much as possible, even the shift key, the ctrl key, the alt key and the fn key - ALL the keys, not just the ones that aren't working.

AHA!!!! I just looked and I've got little blue numbers on those particular keys which means if I hit the fn (function) key those numbers will show up. Your function key has to be stuck! On my computer it's the furthest key to the left on the bottom row!