Mathematicians are scientists, too! Challenge your brain today with this fun math activity!
Materials:
Your brilliant brain!
Directions:
Prime numbers are numbers that are only divisible by themselves and 1. Divisible means that when you divide, you get a whole number as the answer. For example, 6 is divisible by 1, 2, 3, and 6 because
6/1 = 6
6/2 = 3
6/3 = 2
6/6 = 1
But 6 is not divisible by 4 or 5 because
6/4 = 1.5
6/5 = 1.2
So, we know that 6 is not prime. Some examples of numbers that are prime are 2, 3, 5, 7, 11, 13,...
There are actually infinitely many prime numbers. The first recorded proof of this was written around 300 BC (over 2000 years ago!) by a philosopher and mathematician named Euclid. To prove this, he used a technique called “Proof by Contradiction.” With this technique, you first assume the opposite of what you’re trying to prove, and then you show that that is impossible. If the opposite is impossible, then you know that what you’re trying to prove must be true. This is a very common technique in math proofs because often what we are trying to prove is very difficult to show, but it's a lot easier to show that the opposite cannot happen. With this proof, we are trying to prove that there are infinitely many prime numbers, so the opposite would be that there are finitely many prime numbers which means they do not go on forever, or in other words, that we could make a list of all of them.
The details of why this is impossible are too involved for this video, but be on the lookout for a future video explaining this proof. Or try to figure it out yourself or look it up and read about it! Proofs are the key to all of mathematics!
Prime numbers actually have very important real-world applications in cryptography, which is the study of how we keep online communication secure: everything from emails to passwords, to bank account security relies on prime numbers!
Think Like A Mathematician:
What is the definition of a prime number?
Show why 4 is not a prime number.
Show why 2, 3, 5, 7, and 11 are prime numbers.
Is 27 a prime number?
**Bonus: is 1 a prime number?
More About Prime Numbers:
https://mashable.com/article/why-should-we-care-about-prime-numbers
https://www.cantorsparadise.com/six-proofs-that-there-are-infinitely-many-primes-33037bc2c54e
Looking for more fun at home STEM activities for your young scientist? Check out our workbook full of exciting science experiments and empowering activities!
