University of Cambridge
University of Cambridge: Nrich: Two Primes Make One Square
On this one page website sharpen your logic, prime numbers and square numbers skills while working on this challenge. The solution is available to double check your solution.
University of Cambridge
University of Cambridge: Nrich: Tom's Number
Use the clues Tom gives you to figure out his number. The solution is right there on this one page website.
Calculator Soup
Calculator Soup: Lcm Calculator Least Common Multiple
The Least Common Multiple (LCM) is also referred to as the Lowest Common Multiple (LCM) and Least Common Divisor (LCD). For two integers a and b, denoted LCM(a,b), the LCM is the smallest positive integer that is evenly divisible by both...
University of Cambridge
University of Cambridge: Nrich: A Conversation Piece
On this one page website sharpen your logic, division and prime number recognition skills while working on this challenge. The solution is available to double check your solution.
Purple Math
Purplemath: Lcm & Gcf
Purplemath shows an easy and orderly way to determine the GCF and LCM of any two numbers. Even large numbers won't be a challenge with this method.