Apply divisibility rules for 2, 3, 4, 5, 6, 9, and 10 to multi-digit whole numbers to identify factors and multiples. Identify factors and multiples, and classify whole numbers through 100 as prime or composite, recognizing that 1 is neither. Find common factors and common multiples of familiar whole numbers and determine the greatest common factor and least common multiple for pairs of numbers no greater than 100.