So cube faces were numbered 1, 2, 3, 4, 5 and 6.
There are 6 faces in total and there are two faces greater than 4 (face 5 and 6).
So that would be (desired outcomes) / (total outcomes) = 2 / 6 = 1/3
So theoretical probability of rolling a number greater than 4 is 1/3.
Hope this helps.