When we got to student B we stopped and I asked what number we would be at when we reached student C. Some counted down 7 times to get to 8 and then others shared their strategy of multiplying the number of students to get from B to C (7 students) by 4 (because we were counting down by 4) and subtracting the result from the number that student B said. I hope that exposing students who would count down for each student to an alternate strategy will help them add this to their tool kit.
Next up, Which One Doesn't Belong? I showed them the logo first and asked them which one they thought didn't belong.
The first student said the bottom left because it was pink. The next student said the top right because it was a circle, not a square. The next one said the bottom right because the font was white and the top right also because the font is different. I wanted to make sure they understood that there was a reason for each one to not belong.
Then I showed them their task.
They told me that using a cylinder would be a bad idea as both the surface area and volume involve pi which means that it would be impossible to get either surface area of volume to match that of a prims. They said that they could use triangular prisms. I mentioned that they could draw pictures if they chose to use triangular prisms. And then I let them go.
Well, the Monday morning after March break was perhaps not the best time to give a wide-open task. We did solidify understanding of volume. When they had created one rectangular prism with a particular volume at least one member of each group understood that to get another with the same volume they needed to take the same number of blocks and arrange them differently. That was good. Some groups calculated surface area and found that they were all different. Several groups came up with 3 prisms with equal volume but struggled to move forward from there. One group was doing odd shapes and could have matched volume and surface area. Here are some examples:
I believe this activity could be really good but I would scaffold it more next time. I would have groups randomly choose volume or surface area and work with that as a required criteria. I will work on a handout to go with this where they can list the criteria they are choosing and show their attempts - more of the record of their learning and progress. I also continue to learn how to better serve their needs and bring out the e.