Impossible : An event is impossible if it has a probability of 0.

Outcome : A result of a random experiment.

Probability : A probability is a number between 0 and 1 that describes how likely an outcome is. For discrete events that are equally likely the probability can be calculated by dividing the number of favorable outcomes by the number of possible outcomes.

Unlikely : An event in a probability experiment in unlikely if the probability of it happening is low.

Half : A Half is the number equal to $\frac{1}{2}=0.5.$

Impossible : An event is impossible if it has a probability of 0.

Outcome : A result of a random experiment.

Probability : A probability is a number between 0 and 1 that describes how likely an outcome is. For discrete events that are equally likely the probability can be calculated by dividing the number of favorable outcomes by the number of possible outcomes.

Unlikely : An event in a probability experiment in unlikely if the probability of it happening is low.

Division : Division is the mathematical operation that divides objects equally into groups. More generally $x\div y$ is defined as the number that if multiplied by $y$ equals $x.$

Favorable outcome : In a random experiment the favorable outcomes are the outcomes of the event of which we want to calculate the probability. For example if we want to calculate the probability of throwing an even number with a dice the favorable outcomes are 2, 4 and 6.

Number : A number $x$ is a mathematical symbol representing a quantity.

Outcome : A result of a random experiment.

Possible outcome : Any outcome of a random experiment.

Probability : A probability is a number between 0 and 1 that describes how likely an outcome is. For discrete events that are equally likely the probability can be calculated by dividing the number of favorable outcomes by the number of possible outcomes.