Answer: 2/3
Here are the outcomes that are less than five = {1, 2, 3, 4}. There are A = 4 values here.
Here are all the outcomes possible: {1, 2, 3, 4, 5, 6}. There are B = 6 ways to roll a single number cube (aka dice).
Divide the two values: A/B = 4/6 = (2*2)/(2*3) = 2/3
The fraction 2/3 is approximately equal to 0.667 which converts to 66.7%
