GCF & LCM Challenge

This free printable worksheet challenges 6th graders with mixed GCF and LCM problems on the same page, so students must first identify which of the two is being asked before computing. Numbers reach 100 for GCF pairs and the LCMs stay within mental range.

How to Solve Factors & Multiples

Read each problem carefully: GCF asks for the largest number dividing into both (never bigger than either number), while LCM asks for the smallest number both divide into (never smaller than either). For GCF, list and compare factors; for LCM, walk the larger number's multiples until the smaller number divides one evenly.

You can view the preview of this worksheet below, or download the full high-resolution PDF along with the answer key for easy grading.