Solving for missing numbers is a critical pre-algebra skill that even elementary students can learn! All our adorable robots to guide your child along the way while completing this! On either side of each function machine is a robot with a number on his belly, and a missing answer in his hands. Simply look at the other numbers in each graph to find rule and use it to solve for the missing number! Don’t forget to encourage kids to check their answers their work, applying the missing number to ensure it is correct!