Since the cube is regular (or fair), you expect that every number from 1 to 6 has the same probability - i.e. 1/6 - of being rolled.
So, out of 60 rolls, you expect to see each number 60/6=10 times: you expect 10 ones, 10 twos, and so on.
In particular, you expect to see 10 fives and 10 sixes.