What’s the Capacity?

This week in my grade 4 and 5 math classes, we have been talking about the capacity or volume of different objects. Capacity is a bit of a complex concept when you think about it. How can two things that have an entirely different shape hold the exact same amount of water? We have done a lot of hands on learning with the concept this week. One day we gathered several different size and shaped containers and lined them up in the order that the students thought they should go from smallest to biggest. After the final decision was made on what the order should be, we went outside and of course tested out theories with actual water. Surprisingly enough, I think the kids only overflowed two, maybe three different containers. And then a few of them of course had to get themselves wet on purpose just to see if they could get the teacher worked up.

Oh a different day of capacity experimentation, we tested to see if you could really fit 5 one liter bottles of water into a 5 liter bottle and vice versa. For some reason, my students could not wrap their minds around the idea that I could fill my 1 liter bottle 5 times and empty the 5 liter bottle, so our capacity experiment changed its focus a little bit and became a little more focused on the capacity of the teachers’ bladders. Mind you, teachers will do just about ANYTHING to prove a point to their students when they are trying to drive a concept home. Heather and I were guilty of this stupidity on Tuesday. We decided to prove that there really were 5 liters of water in 1 5-liter bottle which means that you can fill 2 1-liter bottles 2 times and then fill one of them again. Of course the kids wanted instant results in this little experiment so Heather and I simultaneously drank 1 liter of water each so we could refill our water bottles and show that only 1 liter remained in the jug. Somehow the teachers both drinking their bottles at the same time became a competition in the students’ eyes. A competition to which Heather got off to the early lead because she started drinking while I was filling my bottle. The kids were quickly amazed at how fast Heather was downing the water, at which point one of them commented…”YO….Miss Rumley can DRINK!” They were not as easily impressed when I came from behind to finish my 1 liter bottle a little bit before Heather, but were quite impressed at the fact that both of us finished the bottle in under 5 minutes. Heather and I’s stomachs and bladders were not quite as impressed as the kids were…we did manage to keep from throwing up, but it took a very long time before I was ready to fill my bottle again to show that there really was only a liter left in the jug.