If we take a fair 6 sided die and colour 3 of the faces blue, 2 green and 1 red and then roll the die 300 times, work out and estimate the number of times it will land with the green side up.

We can see that in any one throw of the die the probablity that the die will land with green side up is 2/6 because it is a fair dice and so has equal chance of landing on any one of the six faces. Since two of the six are green the probability is 2/6 or alternatively written as 1/3. If every throw has a two in six chance of landing green side up and we throw the dice 300 times we may calculate that the expected number of times green will land face-up is 100 as (probability of landing green side up) * (number of attempts) = (predicted number of times green will land face-up), which is (1/3) * 300 = 100.