Tarsia is a great tool for vocabulary development, problem-solving, etc. Basically, it is a program in which the teacher creates a puzzle that the student cuts up and matches the answers to the questions. It is easy to check for the teacher because when students match up the question with the correct answer, the puzzle will make a new overall shape such as an octogon, triangle, or some other unusual shape. Just another great way to practice vocabulary or review for a test that helps bring variety into the classroom. I just made one for finding the slope between two points. Students were given sets of two ordered pairs, and they had to match up the correct slope for the ordered pairs. Tarsia makes this an effortless job for the teacher. You do have to download the program on to your computer, but it is free.