1. Prime and Composite Numbers

2. When Will I Ever Use Prime and Composite Numbers?
If you are baking cupcakes for a birthday party, you will be able to know if the amount you baked can be divided evenly between your friends.
Will you have leftovers? If it is a prime number, you know there will be leftovers!

3. When Will I Ever Use Prime and Composite Numbers?
On Field Day, there is a certain amount of minutes that everyone gets to be able to get to all of the stations.
The field day planners must know if they can split the time that they have so that everyone can get the same amount of time at each station!
If the number of minutes is a prime number, then there will be extra minutes left over!

4. My only factors are 1 and Me, 5!
What is a prime number?
My only factors are 1 and Me, 5!
A number that only has two factors, 1 and itself.
PR I ME
If you look at the word,
The letter “I” looks like the number 1.
The word “ME” is that the end.
Prime numbers only have factors of 1 + ME!

5. What is a composite number?
A composite number is a number that has more than 2 factors.
Example: What are the factors of 10?
_________________
The number 10 has more factors than just 1 and itself!

6. 2: Prime or Composite?
2 is the first multiple of two AND an even number, so it must be composite, right?
WRONG!
The only factors of two are 1 and itself.
…This makes 2 a prime number!

7. How can we figure out if a number is Prime or Composite?
Let’s start with a hundreds chart
We can cross out the multiples of numbers in order.
What is left, that doesn’t get crossed out, are prime numbers!
We are going to start with counting by 2’s. Cross out each multiple of 2, except 2!
Then we’ll do 3, then 4, and so on.

8. Directions Cross out all of the multiples of 2.
(Remember to skip the number 2, it is prime!)
Cross out all of the multiples of 3.
Cross out all of the multiples of 4.
Cross out all of the multiples of 5, 6, 7, 8, 9, 10, 11, and 12.
Circle the Number 1. It is neither Prime Nor Composite.
Highlight the numbers that have not been crossed out. These are prime numbers! (Don’t highlight 1)