Whenever I help students learn to make equivalent fractions, I always try to replicate my teacher's lesson. This week, I came across a great visual in a Wikiversity article and decided to make a laminated version on 4 x 6 cards, so students could use them with dry erase markers. I think this will help them understand what they are doing and why they are doing it.
February 2011 - Last week I started making the cards reversible by changing from multiplication to division, so they can also be used to reduce fractions to lowest terms by dividing by a form of one. Students have had very positive responses to these cards.