A nice introductory activity on simplifying radicals. File provided is the "answer key". Copy and cut out this 16-square puzzle, paperclip the squares after mixing them up, and have students rearrange the pieces to form the correct 4-by-4 puzzle. All values that "touch" must be equivalent! I have copied puzzles like this on cardstock and laminated them to keep in my classroom as "anchoring activities". I have also simply copied such a puzzle on paper, and had students glue the pieces onto another sheet of paper. Working in pairs is very effective!