Doina Popovici
Math Play: Factors and Multiples Game
A jeopardy style game that students can play with others or alone to practice their skills at identifying multiples and factors.
University of Waterloo (Canada)
University of Waterloo: Cemc: Math Circles: Number Theory Ii [Pdf]
This worksheet provides a series of problem-solving questions that require higher order thinking skills. Questions will include finding the greatest common divisor, and least common multiple.
Math Aids
Math Aids: Factors Worksheets
Great resource for learning and practicing fractions and their different operations. Math worksheets are printable, may be customized, and include answer keys.