Earlier this month Graham Fletcher
and Joshua Greene
got together for a tag team take-down of a textbook lesson on finding the volume of rectangular prisms:
|It never really had a chance.|
Their analysis and make over suggestions are spot-on. And I hate to pile on, but what makes this especially egregious is that exploring volume of rectangular prisms, a major grade 5 content standard, can be, well, fun! Rich and I have had success with activities described here
, and I'll offer up another one that we tried out with the fifth graders last year.
Andrew Stadel has written about the potential that starting arguments in math class
has to reinforce both practice standards
(especially numbers 1 and 3) and engage kids in learning, and I agree. For this project, I collected five boxes and asked the kids to guess their order from smallest to largest as measured by volume. I didn't want the boxes to be too similar, just similar enough that it wouldn't be too obvious.
|I chose these five...|
|...and gave the kids time to get their hands on them.|
With the intellectual need now built, it was time for the kids to resolve the dispute. They first had to estimate the volume of each box...
|...then find the necessary measurements. We decided on nearest tenth of a centimeter to reinforce working with decimals.|
|We let them use a calculator because who wants to do all those calculations by hand?|
|The data was recorded.|
And, due to faulty measuring, improper rounding, and incorrect number crunching, the argument continued to rage!
In fact it took several days for the class to come to agreement on the volume of each box and the correct order. But they were days filled with engagement, collaboration, discussion, and multiple content and practice standards.
The activity isn't all that imaginative, and it's not that hard to prep for. All you need are some boxes, rulers, and calculators. And while it's not as easy as asking the kids to take out their books and do this...
. ...I guarantee you'll have more fun.