Have fun with the greatest common factor and least common multiple this Halloween! This riddle sheet features 17 questions on GCF and LCM..

Each question has either 2 or 3 numbers for which students must find either the GCF or LCM.

Students can use whatever method of finding the greatest common factor and least common multiple they learned to solve the problems – the traditional way of listing factors/multiples, the prime factorization way, or the cake method – it’s completely up to you.. (If you are interested in teaching students the cake method you may want to check out this blog post that explains it.)

For the riddle sheet, students answer the questions and then fill in the letters that correspond with the correct answers to solve the fun Halloween riddle.