In math, probability is the likelihood that an event will happen. It is the ratio of the number of ways an event can occur to the number of possible outcomes.

Probability is expressed as a fraction or decimal from 0 to 1. Think of the following scale when determining the probability of an event occurring:

A probability of 1 means that you are absolutely certain that an event will occur.

For example, if you have a coin, the probability of flipping the coin and it landing on heads or tails is 1. Unless someone has a trick coin, you can be certain that either a heads or tails will show when flipped.

If you flip the same coin, you could also say that the probability of flipping heads is .5 or 1/2. You have 1 chance out of 2 to flip heads. Therefore, you have a 50/50 chance.

If something has a probability of 0, then that means that it is impossible, or there is no chance of the event occurring.

Then, there's all of the other fractions (and decimals) between 0 and 1 that are used to represent probability. As we explore this unit on probability, you will discover that you will always write probability as a fraction.

For most courses in middle or high school math probability is a popular unit of study. Why? Without realizing it, you use probability everyday.

What is the probability that I will get the job?

What is the probability that I will be able to win the contest?

What is the probability that I will get the red gumball out of the machine?

Yes.... you may not have been actually computing the probability when you were 6, but I bet that you were analyzing the probability of getting that gumball or "prize" out of the candy machine.

So, let's take a look at all of the lessons for Probability.

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