Math Fails 2018 Set #4 – 87 new pictures to download

For the 4th year in a row, on August 1st, I am releasing a new set of #mathfails I’ve collected in the last 365 days.  Each year I think I can’t possibly find more math fail pictures to join the other 200+ that I have in previous posts.  Thank you to the #MTBoS and #iteachmath community on twitter I found another 80 or more math fails to share with you this year.  At the end of this math post you can download the Word Doc with all 80+ pictures as well as find links to my previous 3 blog posts.

Still 5 years later, the best thing I’ve put on my walls that students, other teachers, parents and almost anyone looks at and discusses regularly is my #MathFail wall of fame.  For the last 2 years I’ve put 20-30 laminated math fails in my hallway and enjoy watching people regularly stop and try and figure out what is wrong with each picture.  I switch out pictures occasionally since I have somewhere between 200-300 pictures I found over the years.  Below are some of my favorites from between August 2, 2017 and today, August 1, 2018.  If you are looking for a fun idea for the walls of your classroom or school I HIGHLY recommend adding a #mathfail wall to your school.

The most common type of #mathfail

There is one type of math fail that is found and shared with me each year.  I like to call this type the “Here’s a penny, keep the change!” #math fail.  Each is a picture of something for sale that as listed should sell for slightly less than a penny each.  It is a misconception of parts of dollars ($) vs parts of cents (

I dare you the next time you see one of these photos at a store to purchase an item, walk up to the counter with a penny and say “Here is a penny, keep the change!” and walk away.  This year you could have purchased pens, lemons (or DEMONS depending on how you read the sign), boneless wings, pool noodles, Mac & Cheese or peanut butter bars all for less than one penny each.

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Graph Fails could also be #1

Bad graphs are make up a ton of the #mathfails I get tagged in.  Not only are there a lot of them – they also generate a lot of the conversation in my #MathFail display in my schools hallways….Here are a few from this year…

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Hotel Room Signs

Confusing hotel room signs seemed to be a theme this year.  I feel I was tagged in them at least 5 or 6 times.  I only found 2 though when I put the collection of #mathfails together this year.

Where is room 1111?


These 2 #mathfails are great conversation starters around percentages…..

First a Lift ad from this year….

And an old comic…

Zero & Prime

Several fails got at the definition and conventions in mathematics – specifically related to “Is zero a positive or negative?” and “Is one a prime number”

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Math problems also create #mathfails

It is not just tweets, advertisements and store pricing where you can find #mathfails.  #Mathfails are found in our text books and the work we assign our students.  Here are just 3 this year from the #MTBoS community.

Janell really has lost her marbles!

Just no!  Is there a worse context for a math problem this year?  I think not. (but if you have one – tweet me at @saravdwerf – I’d love to see it and add it to next years set!

Amie tweeted this one out  – and she is the daughter of a citrus farmer…. we can do so much better selecting contexts for our math problems…

I’ll leave you with this classic Peanuts cartoon…

Geometry Fails

The vast majority of my collection of math fails has very little to do with Geometry – this year was different and had a few fun ones to offer.  One of my favorite came from this story (click link) from England.     Look at this picture… What do you notice?  What do you wonder?

A quote from the article….

Look at the picture above. What do you think of? 

Do you think of the corner of Stanley Park which divides two great football teams? 

Do you consider that one mast in the ground as a symbol of the different directions in which two great football clubs have gone?

Do you wonder what would happen if certain players in history had taken the blue path instead of the red, and what might have become of them?

Because if you do then you’re not looking hard enough.

What should really be ticking you off about that bloody picture is the footballs on the sign. They might seem fine to you, white polygons rattled on a brown background, but take a closer look.

This article and these signs all over England set off a national petition found in tweets  almost a year ago….

Fake (news) Math Fails

In the era of ‘fake news’ talked about all the time, I’d be lying if I said I did not think some of the #mathfails shared with me were manufactured and fake.  I have zero time to track down accuracy on these – but some of them I suspect were put together by someone.  For example – I feel like someone put a paper ‘1’ in front of 30% at this Target store and took a picture – if they did -Kudos to them as the font accuracy is great.  The height of the ‘1’ is just a touch too long to make me think this is real.  If it is real – please let me live by this Target.

Any mathematics on twitter connected to politicians always makes me wonder if the tweet is real or made up or…..for example…this tweet would be a great math hook to start a conversation about measures of center – but may be a bit too political to have a safe conversation – reading the responses to this tweet though was worth my time for a bit to laugh about math….


A favorite tweak to tasks I put in front of students is to add the phrase ‘Convince Me’ to a picture, visual or problem.  This phrase has opened up a deeper level of discourse in my students as they work to craft convincing arguments for the class.  This is a phrase I could see myself using with some of the #MathFails in the set.

For example – I would turn these three #mathfails into ‘Stand & Talks’ (the best routine I’ve ever used in my classroom – click to read more) to start a conversation.

#1  Mike Flynn tweeted this question out.  (click the link to see others responses and additional links about why you can’t walk up the Washington Monument).

I turned this tweet into a stand and talk with the visual and this phrase “Convince the class that this is a reasonable approximation.”  You can download my Word Doc visual HERE:  Convince Me Math Fails

#2  This meme made its way around twitter a while back and I was tagged with the hashtag #mathfail by several of you.  I think it would make a great introduction math hook to start a unit on exponential vs linear growth.

#3  I feel like I could make an entire day long task comparing surface area to volume in different 3D shapes with this #mathfail.  Here is what my initial stand and talk looks like….

I would follow up students beginning ideas with time for exploration and calculations and ask them to provide evidence to prove their argument.  This also opens up other conversations about why product package design is made the way it is made (transportation, materials used, …..)

You can download all three of the ‘Convince Me’ #mathfails in a word doc HERE:  Convince Me Math Fails

My Pet Peeve – Misuse of the equal sign

I really, really dislike when the equal sign is misused.  This screen shot from the last year from a NBC show – Genius Junior (click to see video link) – that marks a contestants mathematics as he calculates really bugs me.  This is something I try and stop my students doing in their thinking.  This is why so many students have a incorrect conception of an equal sign as a symbol that asks you to calculate whatever is to the left of the symbol.  My wondering is how I could use this screen shot – perhaps in a stand and talk – to correct their understanding of an equal sign as meaning ‘is the same as’ or to see each side as equivalent….thoughts?  Comment below or tweet me @saravdwerf.

Another Pet Peeve – Normalizing making fun of Mathematics

This picture from the back of a bus was tweeted out to me this year!  Really – do we need adds like this to keep the status quo of many disliking math?  Why must this continue.  This is a ‘Math Fail’….Ugh!

I made the sign on the back of the bus a bit larger….check out what it says and what math class is equated to….Ugh, again!

Centering math as white & male fails

I am currently on a journey to better recognize the structures in my world and in education that center and privilege me as a white middle class educator.  Not only do I want to notice structures that leave many others feeling other, outside or not included – I am working on dismantling these structures around me.  I have a long long long way to go in this journey – I, like so many of you, have so many unconscious biases from my years of conditioning in a world that privileges me and denies others – but despite this I am on a journey – there are numerous #mathfails we could find that set up our classrooms and schools for the success of some and as not safe places for others.  One really small thing I can do is use some of the math fails to spark conversation with educators and/or students about why these visuals are damaging.  Here are 2 examples from this year.

The tweet below from the campus of Brigham Young University caused a #mathfail that centered white males as being mathematicians made the Huffpost this year.  You can click HERE to read the story and response of the the organizers.  

This next #mathfail would be great to talk about not only the content, but why the way the graph is made continues to center white people as privileged.  How could you use this visual in your classroom to not just talk about mathematics, but also about the world our students live in and the world we want for them in the future.  If this visual sparks your interest – then you can read a lot more about it HERE.

BONUS!  My Birthday

I did not include this photo in the word doc linked below -but thought I’d include it in this post.  Last September the Minnesota Council of Teachers of Mathematics sent me balloons on my birthday (to school!).  So great!  Right?  I’m a lucky girl!  At the time I was the out-going President of the organization.  Can you catch the #mathfail?

September 2017 I turned 49 – not 50!  But, I let everyone at my school believe I was 50 last year.  When I turn 50 in a month and a half, it will be no big deal.  I’ve felt 50 for the last year.  Thank goodness I am not sensitive about my age.  Despite the wrong year – I will always, always be thankful for anyone thoughtful enough to do kind things.  I live in a state full of the kindness and smartest math teachers anywhere.  Because of them I am a better teacher leader.  May you all have amazing people in your life who make you better too – even if they get your age wrong.

Downloads & Final Thoughts

There are 87 total images this year.  I’ve only touched on less than 1/2 above.  Download the Word Doc or PDF to see all the new ones from this year.  I’ve also included links to my previous 3 sets.  My collection of #mathfails is now over 300 images.  I recommend putting no more than 20 images out at a time if you make a wall of #mathfails for students and others to look at.  I also highly recommend switching out 2-3 every few weeks to keep things vibrant and interesting.

Set #4 – new summer 2018 (see descriptions above)  WORD DOC :  Math Fails 2018 Set 4  or   PDF: Math Fails 2018 Set 4

Set #3 – new summer 2017  93+ images

Set #2 – new summer 2016  72+ images

Set #1 – the Originals collected on or before January 2016  80+ images

Do you have something to add to the math wall of shame?  Tweet me @saravdwerf, email me at saravdw@gmail.com or post using hashtag #mathfail. I would love to add more to my collection for summer 2019 (I still don’t believe I’ll be able to find more than 10 for a year from now….we will see)


Sara VanDerWerf

I am Sara Van Der Werf, a 24-year mathematics teacher in Minneapolis Public Schools. I have taught math in grades 7-12 as well as spent several years leading mathematics at the district office. I currently teach Advanced Algebra at South High School and I'm also the current President of the Minnesota Council of Teachers of Mathematics (MCTM). I am passionate about encouraging and connecting with mathematics teachers. I'd love to connect via twitter.  Join the community.  Tweet me @saravdwerf.

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