I created this function vs not a function puzzle to help my students practice determining if a relation is a function or not a function. I also wanted my activity to perform double duty. I wanted students to be able to use the exact same activity to form relations that were functions and that were not functions.

I was inspired to create this activity by the always inspiring collection of Open Middle problems.

## Function (or Not) Puzzle

Students are given two separate challenges to complete.

Challenge 1: Place the integers between -4 and 4 into the empty spots in the tables to form three relations that are also functions. Each number can only be used once.

Challenge 2: Place the integers between -4 and 4 into the empty spots in the tables to form three relations that are not functions. Each number can only be used once.

I created a set of integer tiles for students to use while solving this function vs not a function puzzle.

One of my motivations for making this activity is a certain EOI question released by the Oklahoma State Department of Education. It trips my students up EVERY SINGLE YEAR. Almost always, they are convinced that the problem is flawed and that none of the sets of data represent a function. In this “open middle” problem, I am essentially having them create functions like choice c and non-funcitons like choices a, b, and d.

## Digital Versions of Function vs Not a Function Puzzle

In 2020, I used this activity with my Algebra 2 students to review the definition of a function. I created a Google Slides version. I assigned it via Google Classroom, and it seemed to work quite well. I missed being able to circulate around the room and fix misconceptions right away, but I was happy to still be able to do one of my favorite activities even if it had to be in a different form.

## Free Download of Function vs Not a Function Puzzle Activity

Function vs Not a Function Puzzle (PDF) (1946 downloads)

Function vs Not a Function Puzzle (Editable Publisher File ZIP) (746 downloads)

## Puzzle Solutions

I intentionally do not make answers to the printable math puzzles I share on my blog available online because I strive to provide learning experiences for my students that are non-google-able. I would like other teachers to be able to use these puzzles in their classrooms as well without the solutions being easily found on the Internet.

However, I do recognize that us teachers are busy people and sometimes need to quickly reference an answer key to see if a student has solved a puzzle correctly or to see if they have interpreted the instructions properly.

If you are a teacher who is using these puzzles in your classroom, please send me an email at sarah@mathequalslove.net with information about what you teach and where you teach. I will be happy to forward an answer key to you.

Michelle Muggridge

Friday 10th of September 2021

Just a note - there's an error in challenge #1. The third table of values has 4 twice which makes it impossible to be a function. :) A couple of my students caught it - I was super impressed.

Sarah Carter

Friday 10th of September 2021

It is actually not an error. If you look above in the post at the multiple choice question I posted, you can read why I created the activity in the way I did.

Unknown

Friday 3rd of June 2016

Thanks for including your planning on the planning. It is rare to see the rough draft of an idea, but it is very cool to catch a glimpse of the creative process.

Erick Lee

Thursday 2nd of June 2016

I really like this activity! If I adjust your starting table of values just a bit, you might be able to ask students to create one linear function, one non-linear function and one non-function. I might give this a try. This fits very well with outcomes from our mathematics 10 course.