this is very easy. you already have the common denominator:
3 2/3 and 2 2/3 both have 3 as their common denominator. then just add it normally:
3 2/3 + 2 2/3= 5 4/3
see how its 4 over 3? that means you have to make another whole:
6 1/3
if u have any questions feel free to ask me!