# Sieve of Eratosthenes Modeling

## welcome

 ASL A sieve is a way of getting rid of something you do not want. Then, you can keep what you want. This program will teach you how to use a special kind of sieve. This is a sieve in math, called the Sieve of Eratosthenes. ASL I like m & m's, but I only like the red ones. When I get a package of m & m's, I get rid of all of the other colors, except red. So, I throw out the brown, yellow, orange, and blue ones. This mean I only have the red ones left. This is kind of what the Sieve of Eratosthenes does. This sieve can help you find a special kind of number, called a prime number. ASL Prime numbers are numbers that can only be divided by 1 and itself. For instance, 2 is a prime number because 2 can only be divided by 1 and 2 evenly. Sometimes prime numbers can be hard to find. Rather than simply guessing at numbers and seeing if they are prime, Eratosthenes came up with a way to find prime numbers. He took a group of numbers and put them through his sieve. That way, he knew that he had found all of the prime numbers in that group of numbers. ASL When doing the model, try to find the pattern. Then, you will understand how the Sieve of Eratosthenes works! ASL In this activity, you will learn what prime and composite numbers are. You will also learn about prime numbers and patterns in prime numbers. You will practice dividing numbers. You will learn about divisibility of numbers. You will also learn about a man named Eratosthenes who lived in Greece. You will learn what the Sieve of Eratosthenes is and how it works. By the end of this model, you will be able to do the Sieve of Eratosthenes all by yourself.
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