I also like a variety of models to teach fractions. My personal favorites are pattern blocks. Like someone mentioned with a different model, I like to change the unit block. Sometimes we use the hexagon as the unit, sometimes something smaller and sometimes I tape two hexagons together and make that the unit fraction. It causes people (not just young students) to really think about what a fraction is. In our district, we moved fraction computation to the intermediate (middle) school. We still teach the concept of fractions in k-5 and we teach simple computation ideas with common fractions (half,tenth,etc.), but our emphasis is on working with decimal computation and understanding. We started doing that when calculators became a major part of our program. We want students to know that 3.4564677 is not larger than 54. It has worked well although our standardized test scores stink on fractions in grades 3-6, in grades 7 and 8 we catch up. Once the middle school teachers realize they have more to do with fractions than they did in the past and As long as you can convince the Board that this is acceptable, which we have to do each year, then it seems to be a productive way to approach the idea of fractions.