Clothesline Math – Logarithm Style

I remember when I first heard about Clothesline Math, I was excited by all the possibilities. And in a few conference sessions with Chris Shore, I saw there was so much more than I had even imagined that one could do with it!

It’s basically a number line, that’s all. But it’s a nice public giant number line which can get kids talking. Today I came back from spring break and before break, students learned about logarithms. However I wanted to have them recall what precisely logarithms were… so I created a quick Clothesline Math activity.

I hung a string in the classroom. I highlighted it in yellow because you can’t really see it in the photo…


I then showed them this slide – explaining the string is a number line…


I then showed them this slide, which explains what they have to do if they get two of the same number. (I brought cute little clothespins, but mini binder clips or paperclips would have worked just as well):


And then I gave them the rules of play:


I handed out the cards and let kids go. It was nice to see they didn’t get tripped up as a class on too many of them, but I got to listen to debates over a few trickier ones, which we collectively resolved at the end.

Here are the cards I handed out: .DOC FORM: 2019-04-01 Clothesline Math – Logarithms

Here is a picture of some of the cards. The two on the left are average level of difficulty. The two in the middle caused my kids to pause… it took them time to think things through (they haven’t learned any log properties yet). The one on the right doesn’t belong on the number one (it is undefined) and the kid who got that card immediately knew that. Huzzah!


Here’s a picture of the numberline at the end.


And… that’s it!

I was excited to try it out as a quick review activity. And it worked perfectly for that!


(Other things of note: Mary Bourassa made a clothesline math for log properties and shares that here. The author of Give Me A Sine blog does something similar here, but has kids create the cards. I couldn’t find anything with basic log expressions — so I made ’em and am sharing them in this post. Chris Hunter has a nice tarsia puzzle that sticks with basic log expressions here, but I wanted to try out clothesline math so I didn’t use that!) But if anyone has others out there involving logs, I’d love to see them in the comments!)



  1. Thank you!!

    We are on spring break now. We will need to review logs after break. They had it down before, but I don’t expect that to have lasted through a whole week away. I hope to try this next Monday.

    1. AWESOME!!! Sue, I meant to tell you I was rereading parts of your book for fun this year and it just made me realize how much I appreciated all the work you put in to create something amazing.

      1. Thank you, Sam. That means a lot to me.

        (We’ve sold a couple thousand copies, which is good. But. I want the book in more hands. And I’m not much good at promoting myself.)

  2. Did you have the whole class work on this at once with one card per student? I was thinking of having groups of 3 or 4 work on the whole set ?

    1. I had the whole class work on it together. I debated doing it in smaller groups, but it felt like a lot longer than the “let’s get back from break” review activity than I wanted it to be. But if I were using it to reinforce concepts after teaching them, I would consider doing it in smaller groups. But I’d have them put them down on their desks in order rather than on a clothesline (so it wouldn’t be public for others to copy), and I would have something for students to do who finish before other students (e.g. create new more challenging cards for the card sort?).

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