Co-Authoring Your Classroom

Welcome back to school! Do you remember how this felt?

If you feel anywhere close to how Nancy feels, click through for some great advice from your friends on Math Teacher Twitter. You’ll see very few people encouraging her not to smile until December and very many people encouraging her to do some math with your students on day one. Great advice. We crowdsourced loads of ideas for those math tasks last year. Please add more there.

As much as I’m curious what happens within the four walls of your classroom on day one, I’m also curious what happens on the four walls of your classroom.

This tweet caught my eye for a couple of reasons:

First, “… like Pinterest threw up in your room” is going to be a hard image to shake.

Second, I love the thought that our students would walk into rooms that aren’t fully authored by their teachers, that the space would be shared and awaiting their co-authorship.

If you have experience or ideas here, please add them in the comments. I’ll add the Feltron Project as my own contribution to this planning potluck, and I’d love to learn more.

Featured Tweets

Let’s Retire #MTBoS [as an INTRODUCTION to Math Teacher Twitter]

2017 Jul 31. I have apologized directly to a number of people for aspects of this post. Among others, I apologized to the organizers of Twitter Math Camp (including Lisa Henry, Mary Bourassa, Tina Cardone, James Cleveland, Daniel Forrester, Megan Hayes-Golding, Cortni Muir, Jami Packer, Sam Shah, Glenn Waddell) for posting it during their camp weekend and distracting even a bit from their efforts. Loads of other people stepped up in unofficial, totally voluntary ways to make TMC an awesome, inviting time, and I regret however much I spoiled their efforts.

This community has also been built and nurtured by hundreds of people in thousands of big and small ways – from huge initiatives like Twitter Math Camp, ExploreMTBoS, and Global Math Department, down to folks who watch out for new Twitter users and say “howdy.” This post wasn’t and isn’t meant to critique any of those efforts, but I realize that it came across that way, and that was wrong of me. Precisely because there are thousands of those efforts, I can’t reach out and apologize to each of you individually for dismissing them, so please accept my apology here. Keep on making this place awesome.

Whatever else you think of this post, the people who have commented on it and whose tweets I’ve excerpted below are real people who have found our name alienating. (Not the community. The name itself.) That’s a problem that countless people in the last few days have told me isn’t worth tackling, or one that pales in comparison to other problems. I respect that opinion. I’d like to work on it anyway, and also work on the other problems. But rather than use my platform here to set a unilateral course, I should have found out who is already doing that work and found out how I could help. I’m generally skeptical of leaders and I’ve never been particularly eager to be one, but that isn’t any excuse for setting a bad example. If you’re doing that work, and if I can help or collaborate, please let me know in the comments or at

2017 Jul 28. Thanks to everyone who helped me think this through, especially the ones who did so in spite of being annoyed and hurt. Much love to you all, and to this place. My current plan is to introduce teachers to Math Teacher Twitter by inviting them to attach “#iteachmath” to a tweet, a tag that is intuitive, pronounceable, and importantly, a declarative statement. Meanwhile, “#MTBoS” has less certain pronunciation and, for newcomers, it has been unintuitive and felt a bit like you’re inviting yourself into a secret club. (Seriously, don’t trust me on this. Read the dozens of tweets and comments I’ve excerpted below.) I hope that the thousands of people who find community around “#MTBoS” will continue to enjoy it! But I’m hopeful that “#iteachmath” will be a better invitation for the hundreds of thousands of math teachers who don’t yet know how great we have it.

The original post follows.


I’m not asking us to retire the #MTBoS (unabbreviated: the Math Twitterblogosphere) the collection of people, ideas, and relationships that has provided the most satisfying professional development and community of my life.

I’m asking us to stop referring to it as “the MTBoS” and to stop using the hashtag “#MTBoS” in online conversations.

That’s because this community is only as good as the people we invite into it. We currently represent only the tiniest fraction of the math teachers in the world, which means we (and I’d like to believe they also) are missing out.

That fraction will stay tiny so long as our name alienates people. And it alienates people.

People don’t know how to pronounce our name. Whenever I use it, I get tweets back asking me what I’m talking about. Whenever I invite new teachers to get on Twitter and search for “#MTBoS,” their confusion is plain at that seemingly random assortment of vowels and consonants, capitalized in seemingly random ways.

This morning I read a tweet from a science teacher named Andrew Morrison. I learned from Andrew that the physics teaching community hashtags their work “#iteachphysics.” I felt such a sense of invitation when I read that hashtag – “This is who we are and what we do. You should join us.” And then I felt envy.

We should be so inviting.

This community of ours has no leader. It has no high council. Each one of us has to be the change we want to see in it. I want to see a more inviting community, a community that doesn’t shroud its entrance behind a hedge or protect its door with a password.

So I’m going to stop referring to my participation in “the MTBoS” and instead talk about how much I love “Math Teacher Twitter.” I’m going to stop tweeting using “#MTBoS” and instead tweet using “#iteachmath.”

No one has to join me, and I absolutely won’t be offended if you don’t, but I hope you will, and I hope you at least understand why I’m doing this. I think this change is necessary for our growth and this is how I’ll try to be that change.

Reservations That I Had About This Proposal That I Don’t Anymore

“#iteachmath” is five more characters than “#MTBoS. That’s five fewer characters for my tweets!”

I accept that those five characters are the cost of a more inviting community.

Twitter users outside the United States will want to use “#iteachmaths.”

The MTBoS has a very, very tiny handful of community members outside the United States as it is. I think we can only improve from here. Me, I’m going to add both “#iteachmaths” and “#iteachmath” to the same column in Tweetdeck.

“MTBoS” includes blogs (the “B”) but “Math Teacher Twitter” just refers to Twitter.

“MTBoS” also fails to refer to Slack, Voxer, or any of the other ways teachers collaborate online. “Math Teacher Twitter” hints at all those ways. It doesn’t try to catalog them.

But I’m a coach / consultant / curriculum author / administrator. I don’t teach math so I’ll feel weird using “#iteachmath”.

Let’s not treat this hashtag like it’s a sworn statement in a court of law. It’s an invitation. It’s how we’ll gather community around a conversation. It doesn’t need to serve any higher purpose than that, and I think it’ll serve that purpose better than anything we have right now.

Featured Tweets

Justin’s tweet seems really, really important to me. Consider the perceived requirements for membership in the #MTBoS vs. #iteachmath.

#MTBoS: who knows, but a blood sample and credit verification is probably part of it.

#iteachmath: it’s right there in the hashtag. That’s it. No guessing. You’re invited.

Via direct message:

I always felt a little worried or unsure about joining the community and when it was ok to tweet #mtbos.

Also via direct message:

I actually had to look up the #MTBoS. I am not a member and not sure I am a blogger. I do have a question for the group. May I ask a question with the hashtag without the membership? Thank you!

And on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on.

Featured Comments

Angel Martinez:

I joined the community of online teachers this last year and attended the national conference. MTBoS felt like a secret society that I wished to be a part of but didn’t know how to get in.

Cathy Yenca:

… my honest-to-goodness first thought about being invited was, “Am I ‘in’ the #MTBoS ‘enough’ to speak about it with these other mathies who seem to be ‘in’ it ‘more’?


This makes me happy. For months when I first discovered #MTBoS, I had no idea what it stood for and felt so left out! And then I had no idea how to talk about it to others. (And usually resorted to “it’s basically math teacher twitter.”)


100% agree…I (found) find #MTBoS “clickish…and therefore offputting…even if/though that isn’t (wasn’t) the intent, it has (had) a mysterious and exclusive feel which made me, a 30 year teacher, feel “out of the loop”

Beth Baker:

Thank you, I’m on board! #MTBoS confuses me and I even know what it stands for.

2017 Jul 28.

This proposal made the rounds among the veterans of, let me try this out, Math Teacher Twitter, and they largely aren’t buying it. No hard feelings on my end. This project has become sharper with feedback from the community.

Here are the four most common responses.

We are inviting, in particular at Twitter Math Camp.

I have no doubt that everyone at Twitter Math Camp who comes within forty feet of Julie or the other organizers will feel warm and welcomed. But TMC hosts only a few hundred math teachers out of millions. What is the best way to invite people into this community who have never sent a tweet? Or who have only watched other people tweet? Too many people find our current approach alienating. Check the featured tweets and featured comments above for a sample. If they bother you, what solutions are you thinking about?

This is their problem, not ours.

If the alienated people in the featured tweets and comments above don’t burden you, or if you think their lack of comprehension at our hashtag and how to use it is their own problem, don’t let this proposal weigh on you for a second more. And don’t feel any guilt from me about it. This is my project, which doesn’t mean it has to be yours.

This won’t fix everything.

Using a different hashtag won’t make everything great. Totally true. I think it’s a necessary step, and an important one since it’s our figurative front door, but it’s insufficient. How can we sufficiently welcome teachers to professional community online? I don’t know, but I’m enjoying that conversation also.

I won’t use #iteachmath because I don’t teach math.

I’ve already addressed this above, but it’s possible that #iteachmath isn’t ever going to feel right for folks who aren’t practicing classroom teachers. That makes a lot of sense to me. I have may have chosen the wrong hashtag for these efforts, but that doesn’t change the reality of all the alienated teachers in the featured tweets and featured comments above. If they weigh on you as they do on me, let me know the solutions you’re thinking about.

I’m not sure if it’ll surprise you to find out that the people most enthusiastic about this proposal have been a) classroom teachers, and b) total strangers to me online. Very few people whose names I recognized. These are people whose ideas may nourish us, people who may need our nourishment also.

So here’s a new proposal: let’s treat “#iteachmath” as the welcoming lobby for new Twitter teachers. When I meet new teachers at conferences or in professional development, I want to recommend they post an idea or a question to a hashtag they’ll find intuitive and inviting. From there, perhaps a bit more emboldened, I hope they’ll venture out towards any number of our other hashtags and communities.

2017 Jul 29. Harry O’Malley has written up a really interesting proposal extending these ideas.

2017 Aug 7. Interesting to see medium-sized groups of educators with fewer than 30 combined tweets and followers popping up on the #iteachmath hashtag. See: Algebra for All; #NCLargeMath

Pomegraphit & How Desmos Designs Activities

Eight years ago, this XKCD comic crossed my desk, then into my classes, onto my blog, and through my professional development workshops.

That single comic has put thousands of students in a position to encounter the power and delight of the coordinate plane. But I’ve never been happier with those experiences than I was when my team at Desmos partnered with the team at CPM to create a lesson we call Pomegraphit.

It’s yours to use.

Here is how Pomegraphit reflects some of the core design principles of the teaching team at Desmos.

Ask for informal analysis before formal analysis.

Flip open your textbook to the chapter that introduces the coordinate plane. I’ll wager $5 that the first coordinate plane students see includes a grid. Here’s the top Google result for “coordinate plane explanation” for example.

A gridded plane is the formal sibling of the gridless plane. The gridded plane allows for more power and precision, but a student’s earliest experience plotting two dimensions simultaneously shouldn’t involve precision or even numerical measurement. That can come later. Students should first ask themselves what it means when a point moves up, down, left, right, and, especially, diagonally.

So there isn’t a single numerical coordinate or gridline in Pomegraphit.

Delay feedback for reflection, especially during concept development activities.

It seemed impossible for us to offer students any automatic feedback here. After a student graphs her fruit, we have no way of telling her, “Your understanding of the coordinate plane is incomplete.” This is because there is no right way to place a fruit. Every answer could be correct. Maybe this student really thinks grapes are gross and difficult to eat. We can’t assume here.

So watch this! We first asked students to signal tastiness and difficulty using checkboxes, a more familiar representation.

Now we know the quadrants where we should find each student’s fruit. So when the student then graphs her fruit, on the next screen we don’t say, “Your opinions are wrong.” We say, “Your graph and your checkboxes disagree.”

Then it’s up to students to bring those two representations into alignment, bringing their understanding of both representations up to the same level.

Create objects that promote mathematical conversations between teachers and students.

Until now, it’s been impossible for me to have one particular conversation about the tasty-easy graph. It’s been impossible for me to ask one particular question about everyone’s graphs, because the answer has been scattered in pieces across everyone’s papers. But when all of your students are using networked devices using some of the best math edtech available, we can collect all of those answers and ask the question I’ve wanted to ask for years:

“What’s the most controversial fruit in the room? How can we find out?”

Is it the lemon?

Or is it the strawberry?

What will it be in your classes? Find out and let us know.

2017 Jun 16. Ben Orlin adds several different graphs of his own. Delete his objects and ask your students to choose and graph their own. Then show Ben’s.

This Is My Favorite Cell Phone Policy

Schools around the world are struggling to integrate modern technology like cell phones into existing instructional routines. Their stances towards that technology range from total proscription – no cell phones allowed from first bell to last – to unlimited usage. Both of those policies seem misguided to me for the same reason: they don’t offer students help, coaching, or feedback in the complex skills of focus and self-regulation.

Enter Tony Riehl’s cell phone policy, which I love for many reasons, not least of which because it isn’t exclusively a cell phone policy. It’s a distractions policy.

What Tony’s “distraction box” does very well:

  • It makes the positive statement that “we’re in class to work with as few distractions as possible.” It isn’t a negative statement about any particular distraction. Great mission statement.
  • Specifically, it doesn’t single out cell phones. The reality is that cell phones are only one kind of technology students will bring to school, and digital technology is only one distractor out of many. Tony notes that “these items have changed over time, but include fast food toys, bouncy balls, Rubik’s cubes, bobble heads, magic cards, and the hot items now are the fidget cubes and fidget spinners.”
  • It acknowledges differences between students. What distracts you might not distract me. My cell phone distracts my learning so it goes in the box. Your cell phone helps you learn so it stays on your desk.
  • It builds rather than erodes the relationship between teachers and students. Cell phone policies often encourage teachers to become detectives and students to learn to evade them. None of this does any good for the working relationship between teachers and students. Meanwhile, Tony describes a policy that has “changed the atmosphere of my room,” a policy in which students and teachers are mutually respected and mutually invested.

Read his post. Great, right? How would you build on his work?

2017 May 26. Okay, okay, we have a bunch of font critics in the comments thread!

Featured Tweet

This is a different approach. The cell phones are in jail. But I admire the incentive for parking your phone.

How I Welcome Newcomers to Online Teacher Professional Development (a/k/a the #MTBoS) and How You Can Too

Here is the promise:

There is a community of math educators that meets online at all hours of the day. They trade support and resources and many of the educators who meet there will tell you it is the most indispensable professional development they have ever experienced. If you lack support in your school or district, this community might actually get you through. I’m referring to the the Math Twitterblogosphere, or the #MTBoS, an abbreviation that is as unwieldy and charming as the community it names.

Here is the reality:

Where am I? Who are all these people? Is it rude to just say something to somebody? These conversations look interesting but do I just … jump in?

Here is an ugly bit of unexamined privilege:

Loads of people informed me immediately that, nope, Twitter only works that way if you already have lots of followers, if you’re already in the community, and that it also helps to belong to a demographic that is accustomed to being listened to all the time.

People informed me that their first leap into this teaching community was scary, that getting “shot down” was bad, but bad also was simply getting ignored.

I decided I didn’t want to ignore a tweet from a newcomer to the Math Twitterblogosphere. So about a month ago I wrote up the designs for a Chrome extension and hired a freelancer to build it. The extension highlights tweets from users that meet any criteria I choose.

Here is my “Welcome to the #MTBoS” rule. It highlights tweets from anyone with fewer than 100 tweets, people who are likely new in town, so I can make sure they hear from somebody.

The results have been a blast. I don’t break much of a sweat on these welcome wagon tweets. “Never stop tweeting” is my standard greeting, after a more personal remark. Other times I try to connect newcomers to the resources they’re after. Regardless, people are generally really excited to receive these quick tweets.

That’s someone whose day got made because this little Twitter extension made it easy for me to make sure she didn’t get ignored.

You can make someone’s day too. Loads of these newcomers aren’t following me. Many of them are looking for classroom teachers to follow. Many of them are looking for people who are only a couple of years ahead of them in their careers, not ten or twenty.

You’re welcome to install the same extension, without any warranty, and with only the most meager set of instructions. (If I start hearing that a bunch of you want to install it, I’ll give it a proper download page with a proper set of instructions. 2017 May 25: Updated with that page.)

Hey. Good work, everybody. People are writing dissertations about us. People from outside mathematics education are looking in at us as a model for professional community. This place is special. Let’s keep expanding it – its numbers, its representation, and its heart. This is one idea I had recently. What’s yours?

Featured Comment

Michael Pershan offers his work towards community building: comment on more blogs.