Mathnasium is a math learning center for students in grades 2-12, and Mathnasium’s goal is to give each student the knowledge and confidence he or she needs to succeed. Math is very cumulative as new concepts build on earlier ones. If a student misses a key concept, it can cause frustration for years. The Mathnasium method is truly different. We help the students understand math so it makes sense to them in very real ways – and we customize our approach for each and every student while providing strong encouragement.
Today, we are talking about probability. You may remember studying this in school and getting into permutation and combinations and the like. Let’s step back and explore the basic meaning of probability, something students need to understand for the rest of it to make sense.
Probability is the chance something will happen, but what does that mean – how would you calculate it?
Probability = the number of ways you can win, divided by the total number of ways things can happen. So, to calculate probability, all you need to know are these two numbers.
Here are three examples using probability:
1) Let’s do the simplest example using a coin.
What is the probability of flipping “heads” in one toss of a fair coin? How many ways are there to “win”? One. And how many possible ways are there for the coin to land? 2, so the probability is just 1 divided by 2 or ½.
2) Now consider a standard die with the numbers 1-6 on the 6 sides.
What is the probability of rolling a number larger than 4? The only ways to win are 5 or 6, so there are 2 ways to win divided by 6 ways things can happen. So 2/6, which can be simplified to 1/3.
What is the probability of rolling a 7? 0 out of 6 or 0
3) Imagine a box. The box contains 3 red marbles, 4 white marbles, and 5 blue marbles. If one marble is pulled from the box, what is the probability that the marble is blue?
There are 3 + 4 + 5 = 12 marbles overall, so there are 12 ways things can happen. 5 of them are blue, so the probability of a blue one is 5/12.
That’s the best way to start thinking about probability – the number of ways to win divided by the total number of ways things can happen!
Mathnasium of South Tulsa 8032 S. Yale Ave.
Tulsa, OK 74136
(918)574-2222
mathnasium.com/southtulsa
Mathnasium of Broken Arrow1077 N. 9th Street
Broken Arrow, OK 74012
(918)574-2222
mathnasium.com/brokenarrow
