Probability is the chance or likelihood of an event happening.

In class, we’ve discussed and shared plenty of examples in our own lives where probability has played a role in our decision making. Here are some examples:

• Deciding whether or not to bring an umbrella with you into the mall and being faced with having to carry it around with you everywhere, and perhaps you end up not needing it at all.
• Playing the lottery
• deciding what to wear to school based on the weather predictions that day
• Perhaps your parents can related to this (I can!)–debating whether to fill up your gas tank now…or take the chance that the price will increase when you finally get around to going to the gas station

Our fractions/decimals/percent unit weaves itself nicely into probability because probability shows itself in fraction form, decimal form, and quite often in percent form.

Have you heard of something called Gambler’s Fallacy? This is when people believe that a random process, such as rolling a dice, becomes less random, and more predictable, the more it is repeated.

The gambler’s fallacy usually looks something like this:

1. Something occurs, i.e. I rolled 9 even dice.
2. The occurrence differs from what is normally expected, i.e. It is expected that only 4 or 5 of the rolls would produce an even die.
3. Therefore, the occurrence will end, i.e. I will have to roll an odd die soon.

Have a look below at the video that helps explain what this is.