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9 Dots Puzzle

Today I’m excited to share the 9 Dots Puzzle with you. I love puzzles. I also love finding a way to incorporate them into class.

9 dots puzzle

Since the first week of school is rampant with schedule changes (especially this year since we don’t have a guidance counselor), I aim to engage my students in math-y activities that get their minds working but don’t necessarily tie into the curriculum.

I’ve decided to do daily warm-ups this year that students will keep in their interactive notebooks. School started on Monday, and we won’t be setting up our notebooks until tomorrow (Thursday). This means that my students needed a place to keep their warm-ups until notebooks were set up.

Introducing the Warm-Up Divider!

Daily Warm-Up Divider for Interactive Notebooks

At first, I wasn’t sure what to put on this divider. Then, I realized I could put warm-ups ON the warm-up divider. Can’t believe it took me so long to think of that!

I did this for both my Algebra 1 classes and my Chemistry class. The divider pictured above is for Chemistry.

On Tuesday, I assigned them one of my favorite brain teasers: the nine dots puzzle.

Without lifting your pencil (or dry erase marker), draw four straight lines that pass through all nine of the points.

Since this one is a bit tricky, I decided to make them a dry erase template that would give them lots and lots of chances to try and solve the puzzle.

I figured if they had to draw and erase too many times that they would just give up.

Here’s what I came up with:

9 Dots Puzzle (Nine Dots Puzzle)

When I gave my chemistry students the option to use the dry erase template yesterday, almost every kid chose to use it!

9 Dots Puzzle (Nine Dots Puzzle)

I think only one student went without, but he came in late anyway. I’m assuming he just ended up copying off of the person sitting next to him…

9 Dots Puzzle (Nine Dots Puzzle)

Each table’s folder had templates inside. Kids just had to slide the template of the 9 dots puzzle into one of our dry erase pockets.


dry erase pockets

I cannot imagine teaching math without my dry erase pockets! They instantly make any activity more engaging and save me countless hours at the copy machine since I can use the same class sets of copies year after year.

Here are my current go-to recommendations:

If you don’t have a classroom set of dry erase pockets, you could also use heavy duty sheet protectors. But, I highly recommend investing in a classroom set of the pockets since they are so much more durable.

The kids really struggled with the 9 dots puzzle, so the dry erase template really paid off!

Want even more puzzles for your students? I have an entire page of printable puzzles.

Free Download of 9 Dots Puzzle Dry Erase Template

Looking at this puzzle around Halloween? I’ve got a Halloween version of this puzzle called 9 Pumpkins!

Nine Dots Puzzle (PDF) (2710 downloads )

Nine Dots Puzzle (Editable Publisher File ZIP) (1135 downloads )

Puzzle Solutions

I intentionally do not make answers to the printable math puzzles I share on my blog available online because I strive to provide learning experiences for my students that are non-google-able. I would like other teachers to be able to use these puzzles in their classrooms as well without the solutions being easily found on the Internet.

However, I do recognize that us teachers are busy people and sometimes need to quickly reference an answer key to see if a student has solved a puzzle correctly or to see if they have interpreted the instructions properly.

If you are a teacher who is using these puzzles in your classroom, please send me an email at with information about what you teach and where you teach. I will be happy to forward an answer key to you.

More Dry Erase Puzzles


Thursday 24th of August 2017

These are fantastic! I love these brain teasers. They're tricky, but doable. I think the 9 dots puzzle is a great puzzle to do with geometry students when learning about collinear points. Is your husband also doing brain teasers this week?

Sarah Carter (@mathequalslove)

Sunday 10th of September 2017

He did about a day or two of brainteasers and then jumped straight into curriculum.


Thursday 24th of August 2017

Sarah, It is so cool that you are teaching 9th graders for most of your day this year. I am also teaching 9th graders for my entire day this year :-) I am also determined to get started blogging this year about my class instead of just enjoying the benefits of improving my teaching by everyone else's posts. Now that I finally finished my dissertation, and I am sort of settled in my new school, I will really want to make the time. Best wishes for a wonderful year! Love the idea of the warm-up section in the notebook. I do a spiral homework for the week and students do their warm-ups on the back of their homework paper. That way they are ready to go editing homework as soon as we go over the warm-up. I give bonus points on the homework for the warm-ups.

Sarah Carter (@mathequalslove)

Sunday 10th of September 2017

Thanks Diana!

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