A standard number cube is a die.
The sample space or total number of possible outcomes for a die is six(6).
Probability of an event, say E, is given mathematically as:
[tex]P(E)=\frac{\text{number of favourable outcome}}{\text{Sample space}}[/tex]Hence, the probability of obtaining a 5 is:
[tex]P(5)=\frac{1}{6}=0.167[/tex]