NORMAL MODE: Increment/Decrement numbers

NORMAL MODE: Increment/Decrement numbers

How do you change 23 to 33?
Probably you press "r" with cursor under 2 and then "3". But!
How you change 99 to 100? In this case you need to go to Insert mode or some other variants. But it the simples way on my opinion:
CTRL-a Increment number right of the cursor
CTRL-x Decrement number right of the cursor