Here is a great way to practice comparing fractions with unlike denominators using the least (or lowest) common multiple method. Cuisenaire Rods help make it visually obvious what we are talking about.

Be aware, though, that this is not an activity for those who have just recently been introduced to Cuisenaire Rods or fractions. This should be done after much play/work with both first so that children understand what the rods stand for.

In this free math video, you’ll watch my 6 and 8-year-old make the connection on their own that when you add fractions with different denominators, you need to find the least/lowest common multiple of the denominators. It is so amazing to me to see them figuring these things out on their own. I remember being confused about this stuff in school because it was just a bunch of rules to memorize without explanation of WHY. My kids understand the WHY and so they are able to come up with the rules on their own. AMAZING!