Last week, my students completed this Tarsia puzzle on rational exponents and it was a hit. The level of difficulty was appropriate and the kids were able to do it rather independently.
In fact, they enjoyed the Tarsia so much that I decided to make some blank templates. Last night, their homework was to design a Tarsia with any problems that involved the laws of exponents. Today, they got some time to work in teams to verify the accuracy of their puzzles. Then, I collected them and checked through to make sure they were in fact correct. I found about 25% of them were perfect. The others typically had a small mistake. I made copies of the correct puzzles and we'll make them available for practice tomorrow. One of the best parts is that the students have helped me out by differentiating the puzzles- some are much harder than others and I'll let the students know which are which so they can choose based on their comfort level. I can see using this for many other concepts. I might also make this available as an "early finisher" activity and provide a list of potential topics.
Here are the templates. (Yay, I've posted something to #Made4Math for the first time in a long time.) I started my students off with the triangle template due to the complexity of the exponent problems we've been working on. The squares would be appropriate for shorter problems or for students who need an additional level of difficulty.