This chapter introduces the concepts of randomness, which are numbers that no one can guess the outcome before it happens and that every value is equally likely to be expressed. In order to understand randomness in a better way, we need to know they key terms, that are: ● Simulations: a simulation is a way to model random events, such that simulated outcomes closely match real world outcomes. By using several tools such as a calculator by pressing math→prob→randInt(first integer, last integer, number of integers). ● Trial: this is the performance of a single experiment in which all the values were equally likely to appear, for example, tossing a coin. ● Components: the building blocks of a simulation: first integer, last integer, number of integers.