3 + 2 = 6 for me if I choose to define 6 to signify five. 3 + 2 = 5 only for common mathematical definitions of 2, 3, 5, + and =. Otherwise everything is fine, your opponent agreed somewhere at the beginning, that a group of three objects (such as sheep) and two objects will make five objects for our definitions of two, three and five weather we exist or not.