This project compares the speed of different methods for determining whether a number is prime. When entering a number to check, you may also enter an expression (such as 2^17-1). Each of the methods available in the project is listed below: 1. Basic division - Check every integer from 2 to one less than the entered number and see if it is a factor. Very basic. 2. Intelligent Division - Similar to basic division, but we don't check any even numbers except for 2. Only checks up to the square root of the entered number. 3. Sieve of Eratosthenes - This one is difficult to explain, but the gif on this wikipedia page does a good job: https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes 4. Lucas-Lehmer - This one only works on numbers which follow the form 2^n - 1. It uses a special sequence which is explained here: https://www.youtube.com/watch?v=lEvXcTYqtKU
================ IMPORTANT NOTE: ================= This project can handle numbers which are pretty large. However, there comes a point when the numbers are too large to manage. Once the numbers get large enough (we're talking 10+ digits long), Scratch can't accurately perform math operations and you may get a faulty result. For example, 2^31 - 1 is prime but will return "not prime" in this project. Credit: - Uses @Griffpatch's Mathematic Evaluator: https://scratch.mit.edu/projects/23024829/
