I started function tables with 6th grade today. As an introduction to function tables, I used pattern blocks and let them create a table using input (x) as the number of blocks and the output (y) as the number of sides. They started with one block, then two, then three, etc. After they realized the pattern, I gave them bonus numbers like 82 and 1024 to see if they could figure them out by plugging the input into the rule. This was a low skill to start with, but this class needed the scaffolding and use of manipulatives.