Well, this is fascinating.

It's a graph by David Wilson to determine if something is divisible by 7. Check out the link to Tanya Khovanova's blog to see how it works.

"Write down a number n. Start at the small white node at the bottom of the graph. For each digit d in n, follow d black arrows in a succession, and as you move from one digit to the next, follow 1 white arrow.

For example, if n = 325, follow 3 black arrows, then 1 white arrow, then 2 black arrows, then 1 white arrow, and finally 5 black arrows.

If you end up back at the white node, n is divisible by 7."

The comment section over there is just as fascinating.

Smart Board Symmetry

At our new school we have these fancy Smart Board screens and I think it would be awesome to set up a few of them to let students doodle with a symmetry simulator. Here are some that I've found while I'm at home that I want to test out in my classroom.

For the littles:

It talks about the type of symmetry. For this we could lower a board to the shortest it can go and let kids play around.

Weave Silk is a pretty one:

On this one you can choose between 0 and 6-fold rotational symmetry. You can also share your results via email. Perhaps there's a way to print designs?

Math Is Fun has one, except I wish it had a full screen option:

I love that you can choose the symmetry: x-axis, y-axis, x=y, x=-y, origin, and none.

Can I Create a Math Festival?

 Long time no see - Since I last wrote here I have changed schools twice and gone from being a special education math teacher to a general ed one. I've gotten my professional license, earned my my teaching middle school math certificate, I've attended a math-art conference, and settled in with one grade and one subject. I teach math to 7th graders. It is an adventure every single day. I typically start strong, lose some wind mid-November, get my act together for January, lose some wind by March, and coast to the end of the year. I'm hopeful that teaching one grade consistently and getting to improve my instruction is concrete and memorable ways will help keep wind in my sails through out the year. I'm also hopeful that I can take on more recreational math activities in addition to my work responsibilities. That said, I plan on proposing a Math Festival/Family Math Night to my principal when we return from break.

My school is incredibly math-focused - creating a new related art this year to help kids develop problem solving skills - and being on us all the time about our rigor. We've pushed back a bit this year because we feel our students are over-tested and we can use the time for better instruction while still collecting data. I hopeful that my principal will welcome the idea of a fun math activity. One where we can bring in the community and engage middle school students to run stations and really learn the math required for what they are presenting. That's my hope at least.

I was thinking it was about time that I dusted this blog off and started sharing the journey - more for myself than anything else. I'm under no delusion that others will read this - I just want a place to store ideas and point other people interested in the same ideas to go to. I've been up and down the internet trying to find ideas. There are so many but not particularly consolidated. This will be my space to do that. Also, to lean into the math of each idea. More than anything, I'm excited to dive into recreational math and learn some things about the amazing subject I get the honor of teaching!

So, here's the preliminary plan:

• Create 17 stations (I like the number 17 because it's prime - for that reason, I also wouldn't mind 23, but I don't want to get ahead of myself - 17 is a big number of stations already and I don't even know if I have support yet)
• Lean into the year 2025 and all the mathematical properties of that number.
• Aim for Pi Day! What better way to have a recreational math festival than by using it to celebrate the most popular math holiday? It's perfect!
• Build on it from year to year - I want to start with a night of fun math and build it into a math symposium with contributions from teachers, students, and community members. One of the coolest things my district does is hold a yearly film festival - I want it to be big like that, but instead of being something for the high school kids, I want my students to own it.
• I guess the actual preliminary plan is get support from Admin... email has been sent... fingers-crossed.