Math = Love: May 2020

Monday, May 25, 2020

Square in Square Puzzle

When looking through my camera roll, I recently found some pictures of a weekly magnetic puzzle that never made it up on the blog this school year. Imagine that...

The puzzle is called Square-in-Square, and it's a creation of the brilliant Peter Grabarchuk (affiliate link).

You are given sixteen rectangles. Among these rectangles, only two can be placed next to one another to form a perfect square with another perfect square depicted on it. Can you find the two pieces? Or will you be tricked by the fourteen imposter pieces?

At the time I discovered this puzzle and typed it up for my classroom, it was available on, one of my favorite online sources for puzzles. That website has since been bought out by a jigsaw puzzle company and turned into a website that redirects you to Amazon to sell you jigsaw puzzles. Thanks to Internet Archive, there is an archived version of the website I can point you to now. Want to browse the other free printable puzzles that used to be available, here's an archived link to the general collection of puzzles that used to be available.

The only flaw I've found with using this puzzle both with a group of teachers at a presentation I gave last summer and with the students in my own classroom is that people don't read the instructions carefully enough. I've had multiple people try and pair up ALL the pieces instead of finding only the two pieces that actually pair up to form a perfect square in a square.

Want the printable version I typed up for my own classroom? You can download it here.

Saturday, May 23, 2020

5 New Things I Tried in my Classroom this Year

Every year I try what feels like a million new things in my classroom. Some are life changing. Others are just meh. I end up doing them one year and decide they weren't worth the effort/upkeep. Part of the problem of having a blog is that I often blog about all these ideas before I really know if they are classroom gamechangers or stupid ideas that turn out to be very impractical in the classroom. I frequently receive blog comments asking about something I blogged about during my first year of teaching that I haven't done first year of teaching. I don't really know how to respond to these comments because this idea that the person is so excited about is to me a dud. 

As I reflect back on this very weird school year, it got me thinking about which of the new ideas I tried that were worth keeping. So, I present to you: 5 New Things I Tried This Year (and am still excited about!) 


One of my most-used new classroom tools this year was a cube timer (affiliate link). I bought mine on clearance at Mardels, but you can find lots of different brands of them on Amazon with different time amounts that will hopefully match how you plan on using it in the classroom. So, how does it work. Flip the cube so that the time facing up is the amount of time that you would like to set a timer for. A timer will automatically start. When the timer goes off, just flip the cube so the blank side is facing up again.

I did ACT practice as daily bellwork this year (something I definitely still need to blog about). On the ACT, students are given 60 minutes to complete 60 math problems. So I wanted to give my students practice trying to spend no more than 60 seconds on each day's bellwork. It was so easy to flip the timer cube at the beginning of each hour. I know I was way more consistent in timing my students this way than if I had tried to use my cell phone timer. Fun Fact: the timer cube I purchased was marketed towards people doing high intensity workouts. Ha ha ha. That's definitely not me.


My students LOVED the math joke of the week that I added to my classroom this year. Students would tell me how much they looked forward to coming into class on Mondays because it meant seeing a new joke. One student would wait for students to come into class, force them to read the math joke of the week, and then raise the flap with great fanfare. Still others would remind me when I had forgotten to change the joke out that week. Whenever they did this, I would give them the binder full of jokes (all of them already in sheet protectors to make the switch-out easy) and let them pick the next week's joke. This felt like such a privilege. They would flip through the jokes, laughing at each one, until they found the perfect joke.

This will definitely be an ongoing thing in my classroom going forward.


My mom found a book binding machine (affiliate link) at a thrift store about two years ago that I currently have borrowed. I used it this past summer to create a custom lesson plan book. It was completely worth the time and effort I put into making it if you ignore the fact that I only got to use 3/4 of the pages due to school shutting down for COVID-19.

The year before this past year, I used a planner I picked up at Big Lots as a lesson planner. It worked, but I got tired of writing in my subject names at the beginning of each week.

Last summer rolled around, and I decided I could make my own and have the subjects written in for the entire year. On top of that, I could customize it for our school calendar and mark out the days that we were out of school or had professional development.

As the year progresses, I highlight hands-on/minds-on activities in yellow. This helps me to keep my pulse on when I've gotten into a rut of just doing notes/homework/repeat. I highlight all my assessments in blue. 

When I showed my principal my lesson plan book during my last observation, he was surprised that it was only filled in up to the current day. I guess this is more of a lesson record book than a lesson planning book. My planning tends to occur on notebook paper and a ton of post-it notes. I use this book as a reference of what we did each day so that when a student comes and says they haven't been here in two weeks, I can figure out exactly what they missed.


Another thing I'm really glad I did this past year was use the binding machine to create a bound copy of the Oklahoma Academic Standards for Math. This was most useful when I found myself in meetings. It was so handy to be able to actually pull out the standards when questions came up instead of just talking about what we thought was in the standards.

I recently closed out my classroom for the summer, and I made sure that I brought home my printed/bound standards book. I'd recommend creating a nice printed copy of your standards to every classroom teacher who hasn't already done so.


I know that there is nothing new at all about this idea. But somehow it took 8 years of teaching to finally get around to creating a Weekly Agenda.

My students did regularly reference the board, and it will definitely be something I continue to keep doing in the future. I think I'll be making magnets for things such as Quiz Days, Notebook Checks, etc. on bright colorful paper so that they stand out more on the Agenda.

Wednesday, May 20, 2020

Factoring Monic Quadratics (when a = 1) Practice Activity

In the Oklahoma math standards, students are first exposed to factoring quadratics in Algebra 1. However, they are only exposed to factoring quadratics where the leading coefficient is 1. These are called monic quadratics.

Image Source: Oklahoma Algebra 1 Standards
Thus, my Algebra 2 students should already be fluent with factoring monic quadratics as we begin to factor more complicated quadratics. But, this is not always the case. For one thing, it's usually been about a year and a half since students have had to factor in Algebra 1. Secondly, the Oklahoma standards are weird in that students factor quadratics in Algebra 1 but don't really do anything else with them. They don't graph quadratics. They don't solve equations with quadratics. This leads to factoring being taught as a sort-of one-off topic that doesn't get practiced over and over throughout the course .

I say all this to explain why I'm spending time on factoring monic quadratics in Algebra 2. Most would use this as an Algebra 1 activity.

Pairs of students were given a Factoring Monic Quadratics Mat which featured six different quadratics to be factored. Ideally, I would have laminated these, but I was running out of time.

I did laminate the factors that students had to choose from. I printed them on colored paper to make them stand out on the mat.

In pairs, students tried to use the choices in the answer bank to factor each quadratic. 

For example, the first quadratic could be factored as (x - 1)(x - 2).

And, that's all there really is to the activity. It's nothing extraordinary, but it was a great way to measure where my students' factoring skills were. 

If I were to do this activity again, I would make multiple factoring mats that used the same set of factoring cards. Then, when a group finished early, I could automatically give them some new challenges to complete.

I'm currently planning for a new prep for next year, so this isn't at the top of my to do list. Bill Carrera shared some sets he created on Twitter after I posted some photos of my students completing this activity. Be sure to check them out

It was interesting to see my students take different approaches to these puzzles. Some tackled the puzzles in order. Others jumped around. A surprising number of them fell for my distractor choices which told me two things. First, I picked good distractors. Secondly, it was a very good thing we were spending time practicing these factoring problems in class.

Want to try this activity with your own students? I have uploaded the files here

Tuesday, May 19, 2020

Pi Day Palooza - A Collection of Ideas for Celebrating Pi Day in the Math Classroom

You may be thinking to yourself that I've lost it. It's May. Why in the world is Sarah posting about Pi Day?!? Well, this post has been on my to do list since late February. And, then you guys all know what happened in March. The world went crazy. The last day I saw my students in person was March 12th. And, Pi Day was the last thing on my mind. Instead, we spent the day speculating about this COVID-19 virus that the news couldn't stop talking about. We talked about upcoming travel plans that may or may not happen. We discussed when we might see each other again if school did have to shut down. I think a lot of us were kinda excited about the prospect of a two or three week Spring Break. Oh how wrong we were. We didn't know just how much the world was going to change. I remember realizing how it was the least celebrated Pi Day I had ever seen in all my years of being on Twitter. All this time of self-isolation has given me time to go back through my to-blog-about list and make some stuff actually happen.

I've already decided that if I get to, I'm going to go all out for Pi Day 2021. So I'm publishing this post now so it's ready to go for next March. Much like my Math-y Christmas Ideas post, this post is a compilation of Pi Day ideas that have already been shared in various volumes of Monday Must Reads. I've put all the Pi Day posts together in one spot so you can see all your options for celebrating this mathematical holiday. So, if you're a devout follower of this blog and read each and every post, there's nothing new here. Sorry. But, there's probably a post or two that you've forgotten. I know I had, and I wrote every single one of these blurbs!


I am a fan of this calculus-based pi day graphing project that Alisa shared.

Image Source:
RupeleMx challenged his students in Mexico with the Square Pi Puzzle. I love how he also captured the other figures they ended up creating.

Image Source:
Mrs. Richardson shares a great pi day idea - a poster contest. 

Image Source:
Vicki Biarnesen shares a yummy non-pie treat for Pi Day.

Image Source:
Vincent Pantaloni shares a fun fact to share on Pi Day.

Image Source:
Megan Geltner inspires with a Pi Passport idea. Perfect if you're already thinking about how to celebrate the next Pi Day!

Image Source:
Becca Phillips shares an awesome pi day t-shirt idea from her daughter. Sadly, 2020 doesn't appear until 7000 digits into pi...

Image Source:
Yet another pi day idea from PGCPS Secondary Math to file away for next year! Great idea for decorating with some pi day coloring sheets.

Image Source:
Cheryl Tavernelli shares a winning entry in a Pi Day Character Contest. What would your students come up with?

Image Source:
And, check out this awesome photo day opportunity for Pi Day!

Image Source:
I must share this mathematician dress-up contest idea from Renita Bushell for Pi Day. Can you guess the mathematicians?

Image Source:
Mary Platt shares a great water-color based pi day lesson.

Image Source:
I love Becky Roloff's idea of having a Pi Day Coloring Contest.

Image Source:
I love this finding pi activity from Annette Williams.

Image Source:
I love Ms. R's idea of making pi necklaces on Pi Day!

Image Source:
Laura Frcka shares a new-to-me idea for Pi Day: pin the radius on the circle.

Image Source:
I'm super inspired by how Priscilla arranged her desks for Pi Day!

Image Source:
Sabrina Grasso shares a brilliant use for a hula hoop while celebrating Pi Day.

Image Source:
I've seen skylines made of pi before, but Sarah Gyimoty takes it a step further with the first 180 digits of pi!

Image Source:
I am amazed at Lisa Rode's creativity in creating these Pi Day trophies.

Image Source:
Already thinking about next year's Pi Day celebration? Make it a school wide celebration with this idea from Pep Anton Vieta.

Image Source:
I also love this colorful Pi Day display from Jae Ess!

Image Source:
Preparing to celebrate Pi Day? Check out this awesome Pi-Day themed WODB from Zach Armstrong.

Image Source:
Texas Math Teacher shares a fun twist on Tenzi (one of my favorite dice games ever!) that is perfect for Pi Day.

Image Source:
Are you getting geared up for Pi Day? Check out this awesome Pi Day Dingbats challenge from Ms. O'Donnell Maths.

Image Source:
Jacqueline Tishler shares the idea of engaging students with a kahoot on pi facts.

Image Source:
Mariel Mates wants to encourage crafty math teachers to knit or crochet their own pi day scarf that has rows of colors corresponding to the digits of pi.

Image Source:
It's time to start prepping for Pi Day. Here's a Pi Day Sudoku Puzzle shared by Cliff Pickover.

Image Source:
Denis Sheeran shares another idea for celebrating Pi Day that involves a circle drawing contest.  Check out all the details here.

It's never too early to start planning for Pi Day. Wendy Sargent shares some ideas for celebrating.

Image Source:
Already starting to think about Pi Day? Mr. Downin shares a creative idea: hide pi symbols around the school for your students to find!

Image Source:
Elizabeth Raskin engaged her students in a very visual discovery of pi. I've seen a lot of pi-related activities, but this one was completely new to me.

Image Source:

Have other great Pi Day ideas? Leave them in the comments!