That’s how many files you accumulate in 4 years and a week of teaching, apparently.


That’s how many files were NOT on my flash drive when I plugged it into my computer to print something this morning.

My flash drive asked me to format it for use. Luckily, I know a moderate amount about technology and knew that if I did that, I would likely be losing my chance of ever seeing all of my files again. I clicked no.

Somehow, I managed to refrain from bursting into tears on the spot. I googled ways to recover files. I sat and stared at the screen for ten minutes straight. I realized I couldn’t try any of the recovery methods until I got home, because I don’t have administrative rights on my school computers. I went to plug it in to my classroom computer (I was in my office) just to see if it was the computer. It wasn’t.

The bell rang, the day started. I, somehow, did not cry the whole day. I told each of my classes that we were kind of winging it today, that my flash drive had deleted every file I had ever made for them. They were incredibly kind. (I almost typed “stunningly kind” there, but it is no longer stunning to me how incredibly kind my students are in all circumstances whenever anyone is having a tough time. They are the best people. They love so much.) In most of my classes, we had printed notes yesterday to glue in their INBs, and so my students helpfully read me the examples for me to copy on the board so we could solve them together – the reverse of a normal classroom, almost. One activity I did with one class was on the district curriculum in Google Drive, so I found that. The assignment I had projected on the board for Algebra 2 to start at the end of yesterday I had uploaded to their Google Classroom, so I found it there to project it again for today.

Teaching is a profession of rolling with the punches. You can teach through almost anything. Today, I taught through thoughts of having to recreate from scratch every activity, every notes file, every assessment that I had lovingly created in the last four years. I taught through not having materials for students who were absent a few days ago. I taught through thoughts of my grad school application essay (I’m already in the program, but I was very proud of the essay) and my first year teacher end of year district celebration speech being gone forever.


I told Heather, with whom I share an office, and she mourned with me for a minute, knowing she couldn’t do or say anything to fix it. I told other coworkers throughout the day who asked how my day was (I make it an intentional practice to not lie in answer to that question, so today, all day, I said “my day is going pretty terribly”.) I got condolences and offers to send me the files that other teachers had – even if they weren’t my own, they might be something helpful. One of our teachers contacted a friend who repairs computers and updated me throughout the day with ideas to try.

At lunch, I posted on facebook a call for help – did anyone know how to recover files from a flash drive? I described the situation and the messages I was getting to the best of my ability. My sister directed the message to friends of hers. Fellow teachers expressed their remorse. I got some things to try, and some people gave me a list of places to back my files up to in the future. (I feel like such an idiot for not backing up. I know I should. I guess I thought I was invincible because I understand technology fairly well.) A student who graduated in May directed the message to another student who graduated recently, who works with computers. My heart was somewhat buoyed by the knowledge that so many people understood how devastating this situation was, and wanted to try to help.

I watched my principal’s face fall at the end of the day when I told him what had happened, as I was leaving immediately to go try to save things.


The fix suggested did not work, but it gave me an error message that I was able to find later in that same help thread and try another thing, which did work. My files were back and I immediately burst into tears of relief. All of my work was there. All of the games, and notes, and assignments, and resources that I had spent four years carefully selecting to fit my students that I love so much, were back on my screen.

I immediately backed them up. They now live on the original flash drive, on my personal Google Drive account, on my school Google Drive account, and on a new flash drive that one of my coworkers so incredibly kindly gifted me today.


The lessons from today:

  1. BACK. YOUR. FILES. UP. Seriously, if you do not have a backup for your teacher files, please, please, please do it today. Make sure they are in at LEAST two different places, and preferably one cloud storage place that you can access from anywhere.
  2. My students are incredible and kind and forgiving – and they WANT TO LEARN MATH. They could have tried to use this as a way to not do any work today – and some of them halfheartedly suggested it, but then they dutifully shared the equations with me and helped me recreate today’s lesson so that it was as close to my original intent as possible. They also expressed concern and remorse and shared stories of times their phone lost all their contacts or all their photos.
  3. My coworkers and friends are so loving and helpful and kind and caring. I am so lucky to have them in my life. I should mention that the coworker who checked in with me throughout the day is one that I do not always get along with even – but when I was clearly in distress, they were there for me unhesitatingly. The amount of celebratory snapchats I got when I posted that I had recovered the files was astounding. I have great people in my life.
  4. I am so proud of the work I have done the last four years. Today made that abundantly clear. Sure, I could have recreated everything as we went through this year. But I have made some resources that I TRULY love, ones that I think have really made a difference in student understanding and outlook on math. I want to continue to use them. I was devastated when I lost them. I have had worse days teaching for sure, but this was definitely towards the bottom.
  5. BACK. UP. YOUR. FILES. I’ll say it again because I don’t want you to go through the day I just went through. Back ’em up. Do it for me. Comment if you did.

Mathematicians Can Be… (Bulletin Board Resources)




I’ve been struggling a lot with the Charlottesville situation, and other hatefulness that I’ve watched unfold across the country over the summer. I teach at a building full of students that already feel like they don’t belong in society, who are marginalized for one reason or another. They don’t feel accepted, they don’t feel represented, etc.

They come to our building hoping to find a place they can belong, and I think for the most part they find that here.

I was trying to think of any way I could contribute to that environment of accepting, how I could send a message that says YOU BELONG HERE. WE WANT YOU.

This is what I came up with – it’s a small thing in the big scheme of things, but I think it will matter. Too often, our students come in with the idea that math is a thing that is already complete. That some old, dead, white dudes made up centuries ago and has stayed the same ever since.

I want them to start seeing math through my class as a living, breathing entity that is still being explored, discovered, and created today – in many different ways, by many different people.

This bulletin board was born from inspiration from a few other math teachers sharing their resources on diverse mathematicians (like this and this) – and I set off to try to include groups of people that I know my students will identify with. I want them to start seeing themselves as mathematicians. Hopefully this helps in that endeavor.


Ignore my awkward waving pose in the mirror…IMG_1629IMG_1630IMG_1631

Hoping there will be more selfies like this by my students!

I’ve already had some positive responses from people about the board, including people ON the board (which is crazy to me)!



Here are some closer images:








Notice that there are many more people of color throughout the board, but I picked one mathematician to specifically list with that title.


























Here you can download a list of the mathematicians I placed under each category and the slides I created for each mathematician. Both of those files will direct you to make a copy of them to your own Google Drive so you can make any changes you would like to them! I tried to make the bios easily understandable for any high schooler to read. There’s also the attribute titles that I created (PDFPublisher). The board title and the YOU under the mirror were made with a Cricut machine. The mirror is from Dollar Tree!

You’ll notice that I included myself on the board – I debated this for a bit, but decided it was important for my students to see their teachers as also being professional mathematicians (and not as somehow settling for being a teacher or something). Please alter this slide to include yourself! You could talk about your favorite subjects to teach, how you teach, the math you most liked learning…endless possibilities! I included some of my research I’ve been a part of but yours could definitely focus more on your classroom!

Edit: Someone brought to my attention that if you are British and decide to use this…Andrew Wiles would not be foreign! 🙂

If you use these resources to create your own version of the bulletin board, I would love to see pictures! Tweet them @MissMastalio!

Staff Eclipse Party!

Our first staff day back in the building was today: August 21, 2017. AKA the day of the solar eclipse.

Some of the science department and I have been especially excited about it all summer, and when we learned that we had classroom work time during the eclipse hours, we decided to go full on eclipse.

Mrs. Kormann, Mr. Schneider, Mrs. Hughes and I did a shortened lunch break and hurried back to the building to get set up.


At first, there was just the few of us out in the parking lot, getting Mr. Schneider’s telescope (with solar filter) set up and watching the first bits of the sun disappear. I was so excited, I just kept blurting out observations the whole time. “THE SUN LOOKS LIKE A COOKIE!” was my first at this point, because it looked like someone had just bitten off a corner of it!

Slowly, we drew a crowd. Eclipse glasses were passed around, and turns were taken at the telescope as Mr. Schneider worked to keep the Sun centered every half minute or so. It was really remarkable to be faced with the reality of the Earth’s constant motion!

If you were really careful, you could take pictures through the telescope. Mostly, I tried to just take it all in, but I did take a few!

These were mostly at “Oh my gosh, it looks like the Moon, but it’s the SUN!” stage, although one is at “It’s a thumbnail!” stage!

It was so fun to get the chance to nerd out and talk about all the cool things happening with my coworkers. We had a max totality of about 91% in our area, and the degree to which you could see it getting darker and feel it getting cooler was crazy! The cicadas all came out in full force because they thought it was dusk, and everything else got eerily quiet.

I’m determined to get to the path of totality for the next one…


Book Recommendations (Vol. 02)

It’s summer, and I’m on UNI’s campus again for grad school classes which feels simultaneously very odd (I feel very old and it’s making me miss my UNI friends a TON) and exactly like home (every place is familiar, I got to chat with one of my favorite professors and the Honors program director).

It’s also 6 months into 2017, which means we’re due for my quarterly book recommendations post!

Read previous editions:

Vol. 01


I’ve now read 34 books this year, which means I’ve read 19 since my last post!

Here are my top 5 from this quarter:

the princess saves herself in this one – Amanda Lovelace

This is a book of poetry with four parts: the princess, the damsel, the queen, and you.

This was so. Incredibly. Beautiful. and devastating. and empowering. I was hooked instantly by the dedication page, “for the boy who lived / thank you for inspiring me to be  / the girl who survived / you may have / a lightning bolt / to show for it / but my body is a / lightning storm.” (You all know Harry Potter gets me every dang time!) I want to frame prints of half the poems in this book. I want to type out about four of them right here. You NEED to read this. It is stunning.


Under Rose-Tainted Skies – Louise Gornall

Norah can’t leave her house because she is so afraid of everything. She kind of hates herself for it. Luke moves in next door and wants to meet the girl he saw in the window.

I loved this one a lot because it isn’t a story of boy-saves-girl from her mental illness with love or something that is actually nonsensical. Saying more than that would be a spoiler, but I think it’s an interesting portrayal of this type of mental illness, and it’s an own voices novel (which means an author writing a book about a marginalized population is actually part of said population). It’s lovely and funny and odd, and it’s realistic but still beautiful.


Something in Between – Melissa de la Cruz

Jasmine just won a super prestigious scholarship – full college tuition FROM THE WHITE HOUSE – but instead of being ecstatic, her parents get upset. They inform her that instead of being green card holders all these years, they’ve been undocumented immigrants. She can’t go to the scholarship banquet or accept the scholarship. She might not even actually be able to go to college like she’s been working so hard for.

I loved how incredibly real this was for so many students who are living undocumented lives that they can’t even control because it was their parents’ decision. Who have tried so hard to go through the right channels but our country won’t let them be here legally so they’re forced to make a really hard decision. It brings in politicians and how we value immigrants who achieve special accomplishments over other ones, and there’s also a love story because of course there is. It felt like reading this, I was hurt by everything that hurt Jasmine, and it made me really think about how we treat people who contribute to our country every day but that we don’t consider part of us.


Another Day in the Death of America: A Chronicle of Ten Short Lives – Gary Younge

Younge chose a day (mostly) at random. November 23, 2013. He found every person under the age of 18 who died due to gun violence on that day. There were ten. These are their stories. (nonfiction)

This book was so intensely hard to read – I could only handle about 10-15 pages at a time before taking a break. It’s a blunt description of the reality we live in with the constant ready access to guns we experience as Americans. It acknowledges that this reality is not a simple thing to change, and speaks with groups who don’t want it to change (which literally made me want to throw up). Younge tells us about ten children who died before they ever reached 18 because someone got their hands on a gun, and something happened. Their stories aren’t all the same, but they aren’t all different either. But they’re all dead, and this is just one randomly chosen day. I think it’s an incredibly important book. I want you to read it.


If I Was Your Girl – Meredith Russo

Amanda is starting at a new school in Tennessee, so she can get a fresh start as Amanda. No one at her new school knows that she is transgender. She meets Grant, who seems to like her. She makes friends. But she’s terrified that once they find out, they’ll turn on her.

This is another own voices novel and I really think we need more own voices stories about transgender youth because we need to hear their voices. I was captured by Amanda’s character from the start and thought she was funny and brave and real and normal, but going through something so scary and different at the same time. I didn’t love the way this one was wrapped up (or wasn’t…), but I really enjoyed up to the very ending, so this one barely makes my top 5 because I think it’s an important voice that we’re missing in YA fiction.

Dear Students (2016-2017),


It feels like this school year was just suddenly over. I don’t know what happened. You’ve all left the halls and are off on your summer adventures, and I’m reading through my end of year checklist again before I turn in my keys. I miss you all already, even though a lot of you would probably find that hard to believe. This is a message to you as you embark upon your summer.

To the one who barely passed quarters 1-3 of algebra 1 and is earning a B this quarter: look what you had in you all along. Look what you can do. I’m so glad you learned to separate your dislike of math and your ability to do it well. I am so proud of you.

To those who still don’t feel like mathematicians: it’s in you, I promise. You’ve come a long way and you’ll go a long way still. Remember that ‘mathematician’ doesn’t mean ‘I get everything right the very first time I try’, but that it means ‘I keep trying and asking other people for help and starting over and finding my mistakes and learning new tools and strategies and I don’t give up until I figure it out’. You’re still somewhere in the middle of that process, and that’s okay, because the end of that sentence is ‘I figure it out’ and you will get there someday. Just don’t give up.

To those who do feel like mathematicians, now: Keep going. Keep solving problems. Ask ‘what’s next?’ or ‘what else could I find out about this?’ See what else you could know. Don’t set a limit for yourself.

To the class who calls each other sweet dolphins and can get into pedagogy discussions with me after you’ve completed your work: you have been one of my favorite classes of my teaching career so far. I have learned so, so much from you – more than you probably learned from me. Thank you for your perseverance and your jokes and your earnestness. Your attitudes made me confident enough to bring unboiled eggs into the classroom and ask you to break them.

To the ones who have said mine was your favorite class, or that you felt safe in my classroom, or that I was the best math teacher you ever had, or that my class was the reason you came to school: you should know that every time you said that I definitely told one of my friends about it, wrote it down somewhere, and probably cried a little. Those things make me more happy than anything.

To the ones who now automatically correct themselves when they slip up and use the ‘r’ word: I am proud of you for trying to change your habits.

To those who have been brave enough to share with me or the class your truth, your struggles, your selves: You are incredible people. You have taught me so much about what it means to “be yourself”, and about all of the struggles you go through. I am inspired by your fight, by your unwillingness to back down and conform to society’s expectations when they don’t fit you. I am so proud that you continue to be your whole and true selves every day. You know that most adults are too scared to do that, right? You’re incredibly brave and powerful for doing it.

To the ones who always tell me their favorite method of solving quadratics whenever we’re working with them: I don’t even care which one is your favorite, it makes me so happy that you have a favorite. I’m so glad you’ve invested enough of your thought into this to decide which method works best for you. (I’m double glad that some of you have chosen completing the square as a favorite)

To my sports stats students: I hope I’ve gotten you to at least slightly consider the data when you’re arguing with someone about sports. The most fun part has been combining your knowledge of the players and teams in the NBA, and being able to bring you some numbers to help defend the ideas you already have about who’s the best. You should really watch more college basketball, though.

To my graduating seniors: It’s my fourth year teaching, which means that all my tiny freshmen that I had my very first year are graduating. It feels like the last time I will feel quite this way about the graduating class, because all of those students I had my first year teaching hold such a special place in my heart for helping me through all my naivety and blunders and fear. So many congratulations to you, I cannot wait to see what’s next for each of you. I hope you come back to visit.

To the ones who remind me they care: I appreciate you so much. You don’t know how many times that picture of Baymax has been handed to me after a student just yelled at me the last class, or how many times you asked about my trip to visit a friend when I was in a bad mood. The treats from the foods room always make me feel special. Your birthday messages and treats made me happy on a day I couldn’t be with my best friends. Thank you for reminding me how much I matter to you guys. You are the light in my darkest days. Never a day goes by, even the absolute worst ones, where none of you make me laugh. Never a day goes by where none of you make me proud. At least one of you always makes it worth being here. You’re why I teach. You’re why I love my job more than most adults I know.

To all the Mavericks: Wow, this year has been a really tough year for our little school family. Honestly, I’m so proud and impressed of some of you for continuing to show up to school through all of it. It has been so tough at points to keep going. You are all the strongest, bravest, most unstoppable people I know. Don’t let anyone tell you that you can’t make it. Don’t let anyone stop you from your dreams. The people who try to tell you that you’re no good, that you’re a failure, that you aren’t going anywhere…THEY ARE WRONG. Ignore them. Keep fighting. Keep coming back to school. Keep getting support for your academics and for everything you’re going through outside of school. Stick with your friends and family who are encouraging you to move forward in healthy ways. You know you can always find help, hugs, and a listening ear at Mid City.

Let’s keep the Maverick Movement going – I think it’s catching on 🙂



See you in August!


Miss Mastalio

Are My Rules Mutually Exclusive?

Awhile back, I read Sarah Carter’s post about the Guess My Rule activity she used at the start of the school year to build her group work norms for her classes. I really need to do a better job of building these in my own classes next year, but that’s another post. More recently, I saw her post about using these rule cards again with Venn Diagrams

My Algebra 2 students were right in the beginning of their last unit on counting principles and probability when I read this post, and I knew it would be perfect for us to practice the definitions of mutually exclusive / inclusive and the probability addition rules that go with each of those cases.

I really like doing activities that leave some parts of the problem up to chance, so that the answers don’t always come out “nice” or “normal” (I hate those terms, too. In this case I mean that some of the probabilities were often zero or 100%). I think that addressing these sorts of problems in their practice helps better prepare them for any sort of problem that may come at them, even when tests and other assessments normally have “nice” answers. It also forces them to really consider definitions as they work.

So, the first part of their task was to draw two of the rules cards and set up a Venn Diagram of the intersection. They had to decide if the rules were mutually exclusive or if they were inclusive, then use the proper probability rule to calculate the probability of rule 1 OR rule 2 being true out of the deck.

You can actually see the student worksheet that I made to go with this really well in this first picture, to see how they recorded their work.


Here’s one that was mutually exclusive:


We were also working on complements of events. For this one, they were asked to set up a Venn Diagram with THREE rules from the deck. Then, I asked them to describe the complement of one of the rules being true, and to find its probability. In retrospect, I should have changed a few things about this part of the activity. First, the labels for the rules need to go by the circles. My students really struggled with transferring their Venn Diagram numbers to their papers because they couldn’t keep track of which rule was which circle, especially if they had drawn their Venn Diagram in a different rotation than the one on their paper.

Second, I made the descriptions of the events too vague, so students really struggled with describing the complement.


I do think this activity was really helpful for my students to practice definitions of mutually exclusive, inclusive, and complement, and to practice using some probability rules!

I’ve uploaded the original file I used here, and a new version with the changes I made after doing the activity here. You can find the Guess My Rule cards in Sarah’s original post here.

Looking Back on the Things We’ve Done…

Yes, that title is from a Backstreet Boys song. I actually think the song works pretty well for the idea of reflecting on our year.

At the end of each school year, I like to have my students write end of year evaluations/reflections on their learning. I feel like it gives them a designated time to really sit and think about the massive amount that they have learned, and to be kind of impressed with themselves!

You can read my post from this experience last year here.

The questions:

  1. What did you learn in this classroom this year? What math concepts did you learn, what study strategies did you learn, what other random things did you learn through the course of our discussions and time together?
  2. What did you like and dislike about the COURSE (Sports Statistics, Algebra 1, Algebra 2 or Intermediate Math).  This should be specifically about the mathematics in the course, your textbook or assigned worksheets, etc.
  3. What did you like and dislike about Mid City in general, Miss Mastalio as a teacher, and the environment of the classroom? (You can be honest here, I will not be offended)
  4. Is there anything else you would like to tell me that doesn’t fit into one of the above questions?

I really enjoy sharing snippets from their responses because it’s a rare moment when they feel proud of themselves, and also because I always cry reading them. My students are the most genuine, most caring people I have ever met and it’s great to see behind the curtain a bit. It’s also nice to look back and have memories of each group of students I’ve taught (I’ve kept all the reflections from every year of teaching so far)

Our building has been through a lot this year, so I think it’s extra important to dwell on the good things that have happened within our community this year and to see the positive impact we’re having.

All answers are unedited from how students wrote them.

Question 1:

(written in highlighter to emphasize) “2 is a PRIME #. Always use parentheses!”

“I feel like the most important thing I learned is that math CAN be fun you just have to have the right approach and group of people to keep you engaged.”

“I learned that if you practice something enough you don’t need ‘studying'”

“You can have friends in unexpected classes. You can make jokes and games out of everything. You can have fun with everything as well.”

“I learned how to do math that I never knew existed. I also learned how to be a good student and listen to the teacher when they explain things”

“I think I might even like math better now”

Question 2:

“I got a lot more comfortable asking questions which helped me do a LOT better”

“I liked the question stack activity where we just solved the problems in the pile”

“Algebra 1 is great I really like the hands on learning and the fun activities in this classroom it really helped me learn” (wait, but did you read that? ALGEBRA 1 IS GREAT?!?!?!? my heart!)

“I sucked at graphing, I always have but with the help I got I figured it out and it was easy. I’m definitely gonna use these concepts next year.

Question 3:

“I like Miss Mastalio as a teacher and now the people in this class and just everything in this class. The aura, the vibes, the feelings.”

“Miss Mastalio offers a really comfortable, judgment free zone, and when paired with small class sizes it has been perfect for me to start truly understanding and even liking math.”

“I liked that Mid City has good teachers”

“I like that there are soo many people who actually care + are there to help”

“I like that no one bullies me here”

“I thought Ms. Mastalio was very funny and nice because she accepted my artwork even when it was bad” (it wasn’t bad, I have pictures of Baymax all over my room because of this student)

Question 4:

“I freaked out a few times in my head but this has been the most comfortablest I have ever been at math.”

“I like the way the room is set up, it’s easy to get around”


I think next year I would like to add parts to this reflection that are more specific to each class – ask what their favorite standard was and list all the ones we covered, for example.