I have created a problem-solving website called Math Spies where students solve math problems to capture criminals. In Episode 5, students use function tables to solve coded messages. I have a free version of the worksheet where students can fill in the function tables from the website.
I am a third generation public school teacher who has been in education since 1987. I have taught elementary students full time for 20+ years. I am also a freelance curriculum writer. You can contact me at mrs.mjbauer(at)gmail(dot)com.