This post is an extension of a previous post. For the background story to this post, it will be helpful to read THIS POST first.
The original Noticing and Wondering from the launch of the lesson:
Here are some expanded descriptions of the student work:
Chose numbers strategically to make it easier for themselves:
These two girls were great because they wrote out the paragraph first with the blanks left to fill in after they made a decision on their numbers. You can see the erased 5 in the second blank. When I asked them about it, they said 25 in a class seemed like too many but they couldn’t make the class too small to each get more than 1 bar.
These two were concerned with the number in each box. They said they knew 6 usually came in a box so they just did 4 boxes and then wrote the students in last to make it easy division.
These two were done SUPER fast so I gave them 5 more bars to try and decide what they wanted to do with them. They didn’t do any written work, but asked me how they divide something up into 5 pieces because then each student could get a piece. “We know halves and fourths, but that is not 5 pieces.” After playing around with “fiveths” I gave them the word fifths and they wrote down 1/5.
These two partners were so interesting because when I walked by the first time they had chosen their numbers together, but when I went back the second time, their computation was completely different. I absolutely loved that and asked them to explain their strategy to one another and asked how they were the same and how they were different. The difference was more about the look of their work, but they agreed they were the same because it was still how many 30s were in 63.
Chose numbers randomly:
…and then they worked together on breaking the extra 3 into 10 pieces. Because they didn’t know how to name tenths, they went to something they obviously knew something about…percents! We ran out of time to ask how they knew that was 10%, but I have to make a point to go back and ask!
Dealt with the leftovers using fractions:
This one took a while for me to figure out. These two girls finished rather quickly, so I asked them if they could share the leftovers equally among the kids in the class. It looks like they multiplied the 22 by 2 to get how many pieces they would have if they split them in halves. They each person got an extra 1/2 and they were left with 18 halves. They multiplied by 2 to make them wholes again and ended with 9 bars left over. The sense-making in this one was so incredible to me.
Chose numbers strategically to make it harder for themselves:
When I asked these two girls why they chose the numbers they did and they said they wanted to make it hard! There are so many things I think continued to be fabulous after their initial number choice. The partial products for multiplication and then the repeated subtraction were amazing. I asked them why they were subtracting 26 every time. They said each time they subtracted 26, each student got 1, hence the growing list of 1,2,3,4,5… Absolutely awesome and something I would have never seen if I had given the original problem and the sense-making of what is happening whey you repeated subtract to divide just blows my mind.
To me, every one of these examples, along with all of the papers in the class that day, demonstrated to me how we need to look critically at our math textbooks, think deeply about what we learn about students as they do that work, and adapt materials to allow students to make sense of problems and allow us to learn more about their understandings.
I love this. There’s more common sense and gumption in kids than we give them credit for.
Repeated subtraction is how computers do division.
I love how visible their thinking is! This looks like an interesting and rewarding way to struggle through math! Great job!