I made these cute recording sheets and cards to go along with this activity (which you can find in my TpT store by clicking here).
Have students record the "ins" and "outs" on their recording sheet and then see if they can figure out the rule. Do this for each set of cards.
You can use the colored robot shown here (laminate and use vis-a-vis markers) to demonstrate to your students how to record their answers.
If you have younger students you may want to use symbols instead of letters for the rules. For example, if the rule is A x 7 you could make it
★ x 7 so it is less confusing for them.
These are the cards I used to "feed" the robot. There are five card sets with 100 cards total included in my product. The cards can also be used as a math center game.
The sets include the rules:
Set A: A + 8
Set B: A - 5
Set C: A x 5
Set D: A ÷ 6
Set E: A x 5 + 2
I also included blank cards so you could make your own rules.
You could make all these cards yourself or save yourself some time and for only $4 you can find this product in my store! Click here.