Prime Number Investigation

There are many ways to see if a number is prime. One such way is the sieve of Eratosthenes.

This is a simple algorithm for finding prime numbers in an ordered list up to a given integer. It is a cyclic algorithm which terminates when the given integer is less than the square of the largest prime factor.

An extension of this is wheel factorisation.

Another way to see if a number is prime is to perform trial divisions. The practical way to do this is to divide by all the primes up to that number's square root.

The students are given step by step instructions to follow using prime numbers factors to do trial divisions on various numbers to see if they are prime. by employing spreadsheet formulae.

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Activity instructions (pdf - 605kb)

MS Excel® worksheet (19kb)

CSV worksheet (2kb - if you do not have a spreadsheet application that can open MS Excel® files)

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