Why I love having cell phones in my mathematics classroom!

On April 1, 2017 I wrote a post titled “Why I’ve started teaching the FOIL method again.”  The blog post was my April Fool’s joke to the #MTBoS community.  I got many of you.  I was surprised when I retweeted out a link to the blog on April 1, 2018 that I got many of you a second time.  This post’s title “Why I love having cell phones in my mathematics classroom” may seem like I am pulling another April fools joke on you all.  Untrue.  This blog post is for real.  I do not want to teach in a classroom without cell phones.  Below is why I believe this.

During the last few years I’ve been observed by others maybe 100 times.  I have 2 common comments when people observe my room.  #1:  “I’ve never been in a math classroom where students move so much.”  #2:  “How do you get your students to not use their cell phones in class? I did not see students on them, unless you asked for them out.  Observer comments about cell phone usage in my classroom generated way more questions of education peers than almost anything I do.

In the last month I’ve attended 3 different 2-day PD’s.  As part of each PD we’ve been at some point asked to brainstorm common classroom norms or expectations.  At each PD session educators from all levels and backgrounds complained about the effects of cell phones in the classroom.  Many seem to have given up on trying to keep students off of them.  Many complained about their schools lack of control over them.  Many longed for the days in the past when cell phones were not prevalent.  Many talked about how bad cell phone use was the day ‘Fortnite‘ was released for cell phones.  In these conversations I felt like I was alone in arguing for cell phones in the classroom.  I don’t feel like I have to manage them more than anything else in my classroom and I would totally miss the benefits of cell phones if they were taken away .  I would be bummed if I was at a school that had a rule that did not allow for them to even be brought to the classroom.  Since I am often asked about cell phones in my room, I thought I’d blog about how in the last 5 years since returning to full time teaching they’ve become an integral part of what I do.  I’ll close the blog with some thoughts on how I manage the use of cell phones in my classroom and a few resources for you to use.

Background & Beliefs

I went to college with a typewriter.  A typewriter.   Yes, I’m that old.  My first school had a mimeograph machine (google it) for copies.  We did have a super slow copy machine too (no fancy stuff – no collating or staples).  The TI-81 came out my first year of teaching and I lived through

years of  many calling graphing calculators the end of math education.  25 years later you now find TI-8x products in almost every classroom.  The first half of my career was all done on an overhead.    It has been 10 years since I touched a overhead.  (thank god)  Imagine if I still taught like I did my first year of teaching and had not adapted to what is new and amazing?  Imagine if I was not using my smart-board to create a technology rich classroom?

My job is to adapt to the students I teach and the world they live in and the world I am preparing them for.  Adapting to the current realities of 2018 comes  with amazing things like Desmos Activity Builder and also comes new challenges to manage – Cell Phones has been one of those things the last several years.  How we engage students in the classroom needs to be tweaked.  I don’t lament this.  5 or 10 years from now there will be the next thing I need to adapt to .  A new group of teachers will be annoyed and calling this new thing the end of education and culture as we know it.  Whatever that new thing is, I don’t plan to join the naysayers.  I plan to be with the group of educators adapting to the positive aspects of the new technology.  I choose to look for the good.  Cell phones allow me to engage learners I’ve never been able to engage in my entire career.

When I do speak up for my love of using cell phones educators give me lots of excuses for why they can’t do the same.   “Sara, my students are poor, they don’t have cell phones?”  I disagree.  That may have been true 5 years ago, but look at the data.  I teach at a school with large numbers of students in poverty and high percentages of immigrant students.  Do you know what all of them have?  A cell phone.  I can count on one hand the number of students who do not have a cell phone and all of those students have a parent with a cell phone.  This excuse is not an excuse anymore.  For the very few students have this issue, I work with my school leaders to supplement technology for these students, but honestly I’ve not had to do this at all in the last 2 years.

But Sara, my students don’t have access to WiFi.”  This excuse is true for some students in rural areas, but in cities, this is so untrue now a days.  My experience has been my students are masters of knowing how to get free WiFi (McDonalds, libraries, school…..) everyday.  There is still work to do on this, but the number of student without access has decreased exponentially over the last few years.  I chose to not base what I do in my classroom for the small number of students who can’t or don’t have.  Instead I am investing time into getting resources for these students so all have access.

5 reasons I love cell phones

  1. The Desmos APP.  It is no secret I love Desmos.  I use it often.  When I am using Activity Builder, I usually use a set of iPads or Chrome Books.  When we are just using the Desmos calculator I prefer to have students work on the Desmos APP on their  personal cell-phone (we all downloaded it together the first week of school?  Why?  Simple.  My students (and your students) are way more likely to use Desmos at home if we use it on the platform they will most likely use it outside of the classroom.  My experience is despite using Desmos all the time on computers/tablets in the classroom, there is a fairly large group of students who will not make the jump to the idea that they can also use Desmos on their phone—even if you tell them they can.  Telling is not enough.   I saw huge increases in at home use of Desmos when I started having students use Desmos on their phones regularly in class.  Students do what we model for them.  Side note- I have a classroom set of TI-84’s out all the time for student use.  We use them but at least 1/2 the time we use our phones and the Desmos APP.  Why? What do students have within inches of their body 24/7?  Not a tablet, not the TI-84 you made them buy or even their computer.  The one thing you are assured all students will have with them all the time is their phone.  .
  2. The cell-phone camera APP! – If students did not have cell phones, the thing I would miss more than anything would be their access to the camera on their cell phones.  The students ability to take photos of notes on the smart-board or work they they do on white boards or take pictures of a classmates notes has been a game changer for improving students engagement and success in my classroom, particularity for my EL students.  Often I will say as we are working on something complex on the board up front – feel free to take a picture of the board.  My work on the board has intentional color and I am skilled at creating organized notes – many of my students are not.  Many of my EL students and some Special Ed students will engage in classroom discussions more frequently if they are freed from putting all their energy to writing and digesting lots of information quickly.  My students take so many pictures each day I sometimes feel a bit famous as they snap pics of all the things we do.  My students are paparazzis of math work.  All them time I see my students pulling up pictures of math work and zooming in to study what is there.  It is a new form of studying for math.  Again, guess what my students don’t have with them 24/7 – their notebooks.  What they do have with them 24/7 is the pictures they took of math work with the cameral on their phone  Here are a few other ways the camera on a cell phone helps my students…
    • I have had several students with poor vision or broken glasses use their phone to ‘see the board’  they take photos of everything and zoom in on what they can’t see.  OR they use their phones camera to zoom in on the board at the front of the room, no pictures needed.
    • I have taken myself out of the loop of students getting missed work when they are absent.  I teach my students that a norm in our classroom community is that we help each other. One way we do this is to let absent students take pictures of notes/examples they may have missed.  No need to borrow someone’s notebook.
    • Students take pictures of answer keys to homework assignments all the time.  I love it.  Why – they actually look at them later and it saves time in class – I don’t need to give 10 minutes to look over answer keys, I can just give a couple of minutes – students take pictures of anything they miss.
  3. The Google Chrome (or any other search engine) APP.  If you have not read my blog post on why it is important to teach students to ‘google’, stop what you are doing and go read it HERE now!  One of the best things I’ve every done is to teach students how to find information they don’t know.  In fact, I almost never answer any questions related to math that students should already know.  Instead I tell them to take out their cell phones and look it up. (obviously I also build community in the classroom and also recommend using their peers).  Why have them search instead of me telling them?  One goal in my classroom is to empower students to solve their own issues and find information when they need it.  If I answer all questions, I am the sole-keeper of math knowledge and when I am not around they sit there doing nothing waiting for me to appear.  My goal is to make my role in their learning of math unnecessary.  I of course will always be willing to help them if they go to google and still don’t understand something.   I have taught them tips for googling (read my post for more) so they can find great resources…Here are a few of my tips for them.
    • Be specific – don’t google just google ‘slope’.  Instead google ‘definition of slope‘ or ‘slope formula‘ or….
    • There are lots of words that have different meanings outside of math, so I teach my students to add the word ‘math’ to their google searches.  For example search ‘slope math definition‘.
    • I teach my students to click on Google images.  Many of my students are only 30 seconds away from saying “Oh, I get it (or remember it) now” when they see a good image.  I’ve found google images to be faster to students solving their math issues.
    • I also model how to use/click on the ‘Video’ tab and look for videos to teach/reteach them a skill.
    • I have a lot of language learners in my classroom, so I’ve also modeled clicking on the sound icon that pops up in google and listening to the word 7 repeating the word out-loud at least 10 times.  You may think they won’t do it, but you’d be amazed.  My students want to learn the English language better.  I catch many students popping in an earbud to do this more times than you would think.  If you model it for them a couple of times in class, they will do it.
    • Speaking of EL students.  I’ve taught my lowest language learner EL students to add ‘Spanish’ or ‘Somali’ to any web search.  Often they can find information and images in their first language.  For example:  “multiplying polynomials spanish“.
    • UPDATE:  Thank you to Bonnie Basu for reminding me to have students use ‘Google Translate!  Yes!
  4. Reminder, Calendar and Messaging APPs.  In an effort to help my students learn to manage their student work and create healthy habits that will serve them in college, I often will have students ask Siri to set a reminder in their phone during class “Siri, remind me at 9pm tonight to do my homework”.  I will have them message/text their parents during class to see if they can come in for help the next morning.  I have them take out their phones and put due-dates into their calendars.  When I conference with students about when they will come in to get help or do a re-assessment of a learning talks, if they select a morning time, I ask them what time they need to get up to get here on time and then have them set the alarm in their phone in front of me.  I use these apps a ton of way with students.  As I’ve said numerous times above, my students have their cell phones with them always.  Teaching and modeling them how to use them to manage their lives as students and communicate with parents and peers is part of creating empowered mathematicians in my classroom.  I also model how to set a timer for 20 minutes and then stop when they do homework outside of class (I don’t believe in more than 20 minutes of practice a day, but that is another future blog post).  
  5. The rest.  There are lots of great APPs out here for phones that students and you may use – too many to go into in this post.  For the most part I don’t have students use or download  too many fancy apps.  I find the most useful apps are the simple apps mentioned above.  Here are a few more ways I have students use their phones regularly….
  • I no longer – ever – answer “What’s my grade?” student questions.  I teach them how to look up their grade on their phone.  Again as above, I could show them how to do this on a computer/tablet – but where will they look it up most often, their phone, so I teach them on the platform they will use.  I rarely if ever get asked by students to know about heir assessment or other grades – they usually know moments after I change information online.
  • My students use their phones to check email from me with resources, websites…etc and/or they use their mail apps to email their families with information.  I give students permission to email or text absent student/friends the notes they missed or pictures of the homework assignment or…..Again, I am out of the loop of solving issues I use to have to solve prior to cell phones.  I also have decreased the number of emails from students asking for information, they almost always ask a peer since this is how I model it in class.
  • We also use google drive for a variety of things.  Again nothing to fancy, but all save tons of time and take away excuses for why students can not be working on math outside of class.
  • I also love apps for setting timers in class or picking a random number or…..things like that.

If you have a favorite APP that you have students use on  their phones, I’d love to know about it.  Comment below.

APPs I love (and don’t love) for me, their teacher!

I have lots of apps on my own phone that I use all the time and make me more efficient as a teacher.

  • I love, love my camera app.  I can take pictures of student work or answer keys or screen shots of ideas I want to steal from twitter or……Love it.  I can easily email myself the pictures I find.
  • In the last year I’ve found an app I love way more than my camera app.  If you don’t have ‘CamScanner’, stop what you are doing and download it now.  It takes just minutes to set-up and the jpegs and pdfs you can create are far superior to my phones camera or the scanners at my school and I can use it from the comfort of my home.  No more running down to the copy room to scan something.  I love it because I can easily remove backgrounds from photos and eliminate shadows in ‘Auto’ mode.  Seriously, I use this all the time.  I used it at PD last week to take photos of the 40 sheets of chart paper of notes and ideas we generated and created a pdf of all our work for participants.  It took me less than 10 minutes (and I’m slow). Its free and the best.  Can I gush anymore?
  • I love to use my phones ability to video tape anything.  I video student presentations or a student saying something nice about another teacher and I text these videos to parents or the teachers students are complementing.  I use the video feature to video tape myself so I can look at my practice.  Seriously, no excuses, when is the last time you video taped your own practice and watched it?  Make it a goal to video tape 10 minutes minimum at least once a quarter next school year.
  • Speaking of improving your practice, Annie Fetter’s tweet to put your phone in your pocket and record yourself for 10 minutes and listen to the questions you ask students and listen to wait time is the easiest self-improvement practice you can start as an educator this year.  I don’t know who started this – Annie or perhaps Peg Cagle – both are goddess and if they tell me to do something I will .  You should too.   Do it and let me know how it goes.
  • I love the Remind101 APP for communicating with students and/or students about classwork, due dates, encouragements….. This is probably the best app right now for connecting me and other teachers easily with families -something I was not good at in the past, prior to cell phones. It is an APP I could have mentioned above for students.
  • I love to set reminders and/or alarms on my phone when I get an email about something I need to remember in the classroom.  For example “Siri remind me at 9:55 that there is a fire drill at 10” or “Siri, remiend me to send Jose at 2pm to the counselors office”.  The little bings or buzzes keep me on my game.
  • I often will email/text a parent from my phone a picture of their students work or thinking or a picture of them working – 95% of these are positive messages to families.
  • I am currently loving Duolingo.  If I am asking my students to be persistent in learning math each day, than I too need to be in a daily habit (for at least 5-10 minutes) of personally being persistent with something difficult for me.  I am trying to learn Spanish using Duolingo.
  • Finally, Id dabble in polling apps like ‘Poll Everywhere’.

There are some APPs that lots of teachers love that I do NOT love.  I am on a mission to remove structures in the mathematics classroom that value speed.  Too many students define being good at math as being fast at math.  I am out to change this. For this reason, even though it is engaging, I am never use things like Kahoot in class.

A few notes on managing cell phones:

I get asked about managing cell-phones all them time.  There are dozens of things I do to manage cell phones and most of those things are related to managing my classroom overall.  I am not sure I am the expert, but I’ll share a few ideas that have world for me.

  • One worry some teachers have with phones is ‘I don’t want to embarrasses my students without phones, so unless all students have them I am not going to use them in my classroom’. I have no desire to embarrass any of my students, but if I waited for all my students to have a cell phone in class there would never be a day where this was true.  Something that has worked for me though to honor all students and give them a safe way to opt out is to say the following….”If your cell phone is charged, take it out and__________________.  If your cell phone is not charged, share with a neighbor“.  Saying ‘if your cell phone is charged, gives students a safer out to say to peers vs. I don’t have a cell phone.
  • I have only one rule in my classroom and it is not ‘No Cell phones”.  My one and only one rule/expectation for students in my classroom is that WE WILL DO MATH FOR 50 MINUTES IN THIS CLASSROOM EVERYDAY. 
  • I have the 2nd sign pictured as a sign in my classroom.  I teach this expectation.  During the first few weeks of school we brainstorm and name together what a classroom with this expectation would look like, sound like…etc.  I tell them that anything that gets in the way of us doing math will make me annoyed.  Students name things I might be annoyed with – they name phones, tardies, side talking, not having supplies out…..etc.  I say ‘YEP’.  Here is a word doc with my sign. 50 minutes I use the 2nd one with less words in my own classroom.  if your classes are 55 minutes or more, change the number 50 to the full number of minutes of your class.
  • I am a big fan of managing my classroom with non-verbals (ENVoY) and predictable routines.  If I see a student with a phone out, I catch their attention and don’t say anything, I just point at the sign.  If i need to do it again, I’ll get closer to them and point at their phone and shake my head.  Once in a great while (once a month maybe), I will ask a student who is not responding to put their cell phone on my desk and they can get it back at the end of the hour.  I have not had to involve admin, in years.
  • If my expectation is that we do math for 50 minutes, then I model that every day in my classroom.  I start class immediately when the bell rings.  I We are doing math to within 30-60 seconds of the end of class.  I never give ‘work on homework’ time in class. When I fill up class-time with learning experiences – I have less phone or other issues. Students are allowed to use their phones the last 30 seconds or 60 seconds if class if we finish a bit early.
  • I do not let students listen to music in class ever.  My goal is to build a community of students.  Earbuds are isolating always.  They have plenty of other hours in the day they can listen to music.  I also watched this video from Simon Sinek (see link to my blog and his video in the resource section below) that challenged my thinking on students and technology.  I blogged about it too. (again, see below)
  • During the first week of school we also brainstorm things we can use phones for in math class (see all the things listed above).  I tell them that I will at times ask everyone to take out their cell phones and that for sure is an OK time as long as they are using it for math.  We all take out our phones the first week of school and download the Desmos app and a few others.  In the first weeks of school we get out cell phones together and google math concepts and skills together.  I tell students that I will almost always say yes to using phones if they ask and are using it for something mathy.  For the first month or 2 of class I am on them all the time to ask – sometime in the first few months the out-loud asking becomes nonverbal asking with head nods, pointing to their pocket….etc and with me nodding my approval.
  • At the start of every class I quickly say in a positive tone “Put your phones and earbuds way.  In your pocket or Backpack – not your lap or table”.  Being willing to give one quick reminder most days has eliminated most of my issues.  I do NOT allow phones on the desk/table or lap ever.  Having it out of site, makes it a bit harder to be distracted by them.
  • For the most part I then consistently model and enforce the 50 minutes of math every day expectation.  This means I am (usually non-verbally) calling out every small thing.  I talk to every tardy student every time.  I point at phones every time I see them.  It sounds like a lot, but really if I am on it the first couple of weeks of school, the rest of the year is a breeze.
  • I do not let students charge phones for the most part during class.  I do have a few exceptions to this.  I tell students that if once or twice this year they have an emergency phone call from a parent they may need to take or an emergency charging situation and they talk to me before class I will most likely say yes.  This has eliminated all the students initial concerns like “But what if my mom is going into surgery and I need to call her?”
  • I write on my assessments ‘Phones must be put away the entire hour” and do have a policy that any phones out on test days, even if they finish early will be considered cheating and a score of zero on the assessment.  Being clear, means that I never notice visible phones on test days.  Could it happen, sure, but I am fairly on top of them on these days.
  • Do students sneak phones is my class – sure – but observers in my classroom tell me rarely.  If students are going to rebel for 2 minutes in my room once a week and look at a phone, I don’t care, rebel away.
  • I do not want to waste my time or my students times with all the cool ‘cell phone jail” things all over Twitter and Pinterest.  The 1-2 minutes of lost learning time each day would not result in any less students using phones in my room and I also feel like it focuses too much energy on the phones and somehow makes them more visible.  Tony Riehl did a post on a distraction box (see below) that I would mildly recommend, but for the most part all of these calculator case phone/jail/charging station things are NOT for me – ever.
  • Ultimately, managing cell phones is not stressful to me and I don’t feel like it takes too much of my time.  Believing cell phones have a place in my classroom changed my attitude towards them.  Having a 50 minutes of math everyday expectation that I model and value with the structures and routines in my classroom makes all the difference.  Using non-verbal reminders and permission makes life so much easier.

In 5 or 10 years there will be something new I need to learn to manage that fights for students time and attention.  I will adapt and change by finding the assets of the new and building off of those things.  Today’s distractions are not new in education and we know that.  I choose to embrace what is amazing about cell phones.  Frankly, I could cry talking about them becasue for the first time in my 20+ year teaching career my students in poverty have 24/7 access to things that formerly only middle class and wealthy students have.  My students in poverty can now access a library (Google) any time they want to teach them anything they need.  My students now carry a graphing calculator (DESMOS) with them everywhere.  There is always a way for all my students to contact me if they need to outside of class. There is no excuses anymore to doing math outside of my classroom.  Cell phones have closed some opportunity gaps that existed the first 20 years of my career.  I am lucky to teach in the era of cell phones and am excited for what comes next.  

Additional Resources


In this post I made an argument for using cell phones in the classroom.  I fully expect that some reading this will have different opinions than my own.  This blog post is just what I believe as of July 2018.  I may change my views.  I have zero desire to engage in a debate in the role of technology or cell phones in the classroom.  This blog post is my answer to all the observers in my classroom who have asked about my cell phone beliefs.  It is totally cool with me if you feel differently.

A final note

Technology, like anything else in life is best when it is used in balance with the other things you value in life.   This is a picture I keep next to my desk.  I want to remember to be like the older woman in this photo more often.  I want to put down my own cell phone and be fully present in enjoying the world around me and participating fully with the wonderful people in my life. I want to see my students and not just exist in the same spaces with them.  I too need to use technology judicially.  I am no different than my students.  Perhaps you will join me in posting this photo by your desk.  (this photo is one of 31 from a calendar of photos I blogged about HERE.)  


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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