Dimensional analysis was likely the most useful math skill that I used during my undergraduate science degree. I think it is so important that I really try to drill it into my students' heads! At first the name "dimensional analysis" sounds daunting. They quickly learn that it's not! My students get excited when they learn that they can solve complex problems using dimensional analysis.
The first of these two worksheets introduces students to the general concept of dimensional analysis. Pictures make the concept visual. A guided breakdown of a sample problem models the process for students. Then, they practice the process!
The second worksheet is great for independent practice. I give it as homework the day that I teach the concept. First, it presents a word problem about a road trip to help students see all of the problems that can be solved using conversion factors. Two additional word problems (one about how many free DVDs one can get for a sleepover party, and one about how many heartbeats happen during a lifetime) review the formatting for dimensional analysis.
Thanks for looking!