A single 6 sided dice i rolled find the probability of rolling a 4 or smaller

Smaller of 4 are 1 , 2 , 3

So you have four numbers 4 or smaller:

( 1 , 2 , 3 , 4 )

The probability of rolling a 4 or smaller is:

4 / 6 = 2 • 2 / 2 • 3 = 2 / 3