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.
More work with Cuisenaire Rods to help develop an understanding of fractions. When fractions are just numerals on a page, children get confused. Cuisenaire Rods give them a way to touch fractions as well as to see fractions as pictures.
This free math video shows a simple way to introduce “Improper Fractions” using Cuisenaire Rods. It’s best to do this activity first with only white rods and your “one” rod. My daughter has worked with fraction concepts using Cuisenaire Rods for a couple months so she understands that she can just use a purple rod in place of 4 white rods to represent 4 as the numerator. If this is confusing to you, get the rods out and do this activity yourself! It really does help!