“Function machines” are an excellent, tried-and-true method for introducing inputs and outputs and the concept of functions to students. Enclosed in this resource is:· 6 pages of worksheets with 24 total functions and input-output tables, as well as outputs given requiring “backwards” thinking to find an input.· Increasing difficulty allowing for differentiated instruction.· Examples that include:one-step linear functions with whole numbers; one-step linear functions with decimals;one-step linea