1. Prime Numbers A prime number is a number with exactly two factors The first ten prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29

2. Square Numbers 1×1=1, 2×2=4, 3×3=9, 4×4=16, …. The first 15 square numbers 1² = 1, 2² = 4, 3² = 9, 4² = 16, 5² = 25 6² = 36, 7² = 49, 8² = 64, 9² = 81, 10² = 100 11² = 121, 12² = 144, 13² = 169, 14² = 196, 15² = 225

3. Primes and Squares Fermat, a French mathematician, proved that some prime numbers can be written as 2 square numbers added together E.g. 29 = 5² + 2² = 25 + 4 There are 11 other prime numbers less than 100 which can be written like this Find them! (2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67, 71,73,79,83,89,97 are the prime numbers less than 100)