I just started learning math from 0 and looking for explanation
I have a set {18,...,32} and the task is to find its cardinality. I was thinking that substracting the lowest (18) from the highest (32) would give me the correct answer (15), but it gives me incorrect one (14). It's off by 1. I can't figure it out why is it so? It seems the correct formula is (max_number - min_number + 1).
Manually counting numbers seems that it's true, the answer is 15, but I can't figure out where does 1 go if I use substraction?