A Key element of PEMDAS/BODMAS/BIDMAS/GEMDAS that most schools will more or less ignore or merely gloss over is that neither addition nor subtraction actually have priority over the other and in cases such as 2-2*3+3 you always work left to right for priorities between the two so it's
2*3=6
2-6=-4
-4+3=-1
The same rule applies for multiplication and division but with some exceptions.