First of all, head on over to Mr. Stadel's section on his site to grab the materials for "Algebraic Expressions." You should also watch the introduction video.
I did this activity first with my 7th and 8th grade math support class. I worked solely with 8th graders because the 7th graders were working on some homework.
About to do #clotheslinemath via @mr_stadel with 7/8 support class. Then 6 gr support later on. Reflection to follow! #mtbos pic.twitter.com/1cDWlinl4D— Martin Joyce (@martinsean) November 10, 2016
I started with the numbers out of order. I asked them what they noticed. They said it was like a number line but out of order. I then talked about how before clothes dryers people used to have to hang their clothes outside to dry and used lines like these.
I then put the purple algebraic expressions out in the incorrect order, just like the video suggests. Interestingly, they didn't manipulate the numbers first, even after that first observation. One student figured it out quickly, so I talked to him and students in a later class that if you know the ending to a move, don't spoil it for the rest of the people still watching, or thinking. Also, I had them draw the 2 clotheslines on their paper, which may or may not have helped them, not sure.
The students were keen on figuring out what m was before moving anything. It seemed like they came up with 0m first, then 2m. Students one by one made contributions. I then asked them if they were spaced correctly. I used my 2 fingers and asked the distance between 4 and 7 (they said 3). I then kept my fingers in that position and moved to 12 and 19 and they said it was 7. So, I asked them if it was correctly spaced? Then they adjusted it. Having the cards as folded sheets of paper made it SOOOO much easier to manipulate compared to clothespins which I had used in the past.
I also can't WAIT to do the slope intercept clothesline activity once we are in the middle of Chapter 4 of CPM.
In my 6th grade math support, students immediately worked on putting the numbers in order. The first person put 0m below 0. Then they figured 24 was 2m. One student said that they thought that 24 was the biggest, and it was even, so it had to be multiplied by 2. Then with that knowledge, another student figured m was 12, so 19 was m plus 7. Not surprisingly, the last and biggest obstacle was m/3. They have had trouble dividing and saw m/3 as a fraction, not a division problem, when in actuality we know it is both.
Students remembered from 5th grade that a letter was called a variable and could represent anything. What they later realized that in this situation, the variable could only be one value for it to be true through out the whole number line. I was also impressed that they understood 2m meant 2 multiplied by m, which some of my 8th graders did not know!
There is also a clothesline fraction talk activity, but I didn't use it yet because I'm waiting on seeing how other teachers have used it. I remember in my FAME program this summer, we had benchmarks and each of us was given a blank template to shade a fraction and put it under the correct fraction on the number line.
I also did this awesome Flag Match fraction talk afterwards. I first saw it on twitter and it intrigued me because I have Tongan students in each of my support classes. One was part Fijian so they were wondering where the flag of Fiji was. If you click through to the link, the biggest obstacle is differentiating the Tongan and the flag of Denmark. I wrote down each of their answers, and put checkmarks for people that agreed with others. I liked how Amy said, "the Tongan flag has the least amount of white, so the pie chart must have the most red!" (which it did)
Here is an update