Prime Numbers: Sieve of Eratosthenes Classroom Poster

The prime-number concept is fundamental in math, and in this poster we represent in a modern form one of the most ancient investigations of this idea: The Sieve of Eratosthenes. It shows how prime numbers can be isolated by checking whether any previous primes are factors.

Although the basic concept is easily grasped from the image, there are subtleties that reward a prolonged stare. You'll observe that every number is defined uniquely by its proper divisors, and the number and type of any number's divisors are immediately apparent from the curves that traverse its location along the line. The colored lines intersecting a number represent its prime factors, while the gray ones represent all of the composite divisors.

Beautiful, educational, and ideal for the classroom, school room, club room, or dormitory, this durable poster is an art-quality print on heavy gloss stock. It is suitable for framing, mounting, or hanging as is. (Dimensions: 19in/48cm wide and 13in/33cm tall.) Shipping is free! (United States)