Math = Love: Function Auction Updated

Monday, May 30, 2016

Function Auction Updated

One of my favorite activities from this past year's Algebra 1 class was our Function Auction.  When I originally did this in class, I threw it together at the last minute.  This meant I grabbed a random worksheet off of the Internet and called it good.  Here's my write-up of how the activity went last year.

I'm currently in an "overhaul everything" mood for the next school year.  So, I decided to create my own Function Auction worksheet.  I used images of functions and non-functions from released state questions from Oklahoma, Arkansas, and a couple of other states.

Here are the rules for hosting a Function Auction:

The auction catalog features 12 lots.  

I also made a version with boxes around each lot. 

For extra fun, make auction paddles for groups to use using colored paper and rulers or paint sticks.  

Here's an example from last year's function auction:

If I haven't sold you on the idea of the function auction, I made the function auction catalog into a worksheet.  

Without boxes: 

With boxes: 

Files can be downloaded here.  For the editable Publisher file, you'll need these free fonts: HVD Comic Serif Pro and Aaargh.  The PDF file will preserve the fonts and formatting.  


  1. As a former economist, who studied auctions & game theory, I am loving this idea!

  2. This sounds like a fun way to practice. My students are always perplexed by a vertical line - some students don't see that as failing the vertical line test, but it's a good time to remind them that line have infinite points. Thanks for sharing 😊

  3. I used your idea this year for my pre-algebra 8th graders and they LOVED it!! Totally doing it again this year :)

  4. Thank you, Sarah! I used this today and my class loved it! SO much fun and great to see them discussing each "lot" with their team. Thank you for always being so generous and sharing your great ideas and activities with so many! ~Tracy

  5. I am totally using this in the fall!

    - Elizabeth (@cheesemonkeysf)

  6. I've been waiting to use this for a year and I'm ready this week. How many examples did you do before you did the auction? Did you already talk about the definition and vertical line test before you did this? About how much time do you think this activity took? I'm switchign from block to regular schedule classes and timing is driving me nuts :)

  7. I and my students owe hours of math joy and inspiration to you! Love the activity.

    Do you ask if they are "functions of x, or a specified input?" Lot 12 is a function of t: f(t)=(sin(t),t). I always got confused in high school when we got to paremetric equations because we were seeing functions that dont pass the vertical line test. So I specify to my Alg 1 Ss "function of x".

    Thanks again for all of your amazing posts!

    1. I've never specified that before. Now I know to be more careful!

  8. I want to make sure I understand this game correctly because conceptually I may want to use this for a geometry class. Part 1 is the auction, each team bids on one or more of the 12 items. At the end of the bidding the person or team that has purchased the most Lots wins. Then there is the discussion about whether they are functions or not which is a separate issue and is not connected to the answers for the functions. I just want to make sure I have this correct. Or, do you do the auction and then as you discuss the answers if a team gets it wrong they lose their lot so at the end of the discussion people who have answered the questions correctly keep their lots and from there you determine a winner.

  9. I have a similar question. Do you give the students a "preview catalog" so they see all the lots at once or do you show each lot one at a time?
    Thinking this will work well for Complementary and Supplementary angles! Also wished I had thought of it for right triangles...ah, next year.

  10. I used this for my 8th grade students today and they absolutely loved it!! Thank you for the great idea!