This is the second in a series of posts that blend art and math. Jump in and choose your medium to indulge in creative expression. Many have played with this through the years; a list of references is at the bottom. Thanks to Steve Heller for pinging me to play with squarable numbers and add them to inquiries.link along with some variations.
Warm-up
Grab a sheet of paper and a ruler. Make a square.

Now, split this square into squares. You might do something like this with four squares:

or these with 9 or 16 squares:


Now try to draw a square split into squares that are not all the same size by changing one of the smaller squares above. This time feel free to add some color to your squares.
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Ok, what did you make? How many squares does it have? Here are a couple of ideas:
One with 7:

You can also try joining squares together. Take the 3x3 grid; we can join four squares to change 9 into 6.

Making Patterns - a primer
Now, let's think about the sequences we can form and art we can make with the ones constructed.
{1, 4, 9, 16, 25, ...}






Now, what if you devise your own pattern? Create a rule for what comes next. For example, let's look at a pattern where we take a square that has been split into equal squares (like above), and then we join any middle squares to make a frame:

This would give us a sequence:
{9, 13, 17, ...
What comes next?

Did you say 21? How can we write this pattern? Here are a couple of ways:
- 5 + 4n
- (n + 2)2 - n2 + 1
Check to see if the next one fits how you wrote it - do you get 25?

Activity: Making Patterns - your turn
Now it's time to make some art. You can do this through folding paper, watercolors, quilting, or whatever medium suits you.
- Come up with your method to construct a pattern by dividing and/or joining squares.
- Decide if you will paint just one or many from the pattern.
- Contemplate what the sequence might look like as it goes on. Does it have an end?
- Are there rules to your pattern for how to color it? How many colors do you need so no two adjacent regions share a color?
Here is a gallery of example compositions. How were they made? What came before and what comes next?






More to Contemplate
- Are there other sequences that might start the same, but could go a different way?
- What if you start with something other than one square? Like a 4x4?
- Play around with "what ifs"
- What if you change where you divide the squares?
- What if you add a step to your construction method (like split, join, then split again)?
- Look up your sequence by typing the numbers into OEIS to see if it is there.
- Write your sequence as a formula.
- For example: {1,4,7,10,13,...} can be expressed as 3n − 2 where n is the position in the sequence.
- Is there a sequence where a square is divided into squares that all have different sizes?
- Are there numbers that you can't make by dissecting squares into squares?
Example Art:


Resources and extensions
- Wikipedia has some variations, including Mrs. Perkins' Quilt
- A few who have played with this: Henry Dudeney (1917), John Conway (1964), Martin Gardner (1966), Antonick & Finkel, NYT Numberplay (2013), Math for Love lesson by Finkel (2017), and many others.
- Fun note: to do this post, I went down quite a rabbit hole for how to piece the quilt together.
- Origami papers are a nice tool to play with for this activity - you can cut, fold, and place papers to think about arrangements and dissections.
- There is a tool called Squarrels on Inquiries to explore this. (Note: squarrel is the name because squirrels are fun, and the words square-able, squareable, and squarable all look funny.) This tool has hidden word surprises - type: "fish", "tree", "oregon", "all", "banana".
- Do the same thing, but with rectangles
- What rectangles can be tiled with squares of all different sizes?
- Are there patterns that you can make when the outer shape is a rectangle that you can't with a square?
- There is a tool here for this.
- Do the same thing, but with triangles - here is a tool.
- Try this with L-shapes as well (L into squares, L's into L's)

