Monday, May 13, 2013

"It's a measuring cup because it has numbers on the side!": Messing About with Science Tools

Op., L., D. and E. built a habitat of layered rocks, sand, soil and water in a clear cylinder--an experiment to discover which environment worms liked best. 

Their theory:
"Whichever [layer the worm] likes best, it will be in the most."

A few days after creating the habitat, observing the worm for a while and writing down their notes,  the group was itching to switch up the layers and add more substances.
They drew plans for differently layered habitats, and asked me to get more "test tubes" for the next day.

I emailed Dan--Sabot's Science Specialist--with the group's request and was embarrassed when Dan reminded me that what we wanted were large graduated cylinders, not test tubes. Because, he wrote "...[graduated cylinders] have markings on the side." I promised Dan that I would correct the boys' terminology first thing.

But in the morning when I went to collect the said graduated cylinders, Kara, the middle school science teacher, suggested that I take real test tubes back to the group, claiming that I had asked for test tubes and received something else entirely...

Later, in the classroom:

 Teacher: I asked Dan and Kara for test tubes and this is what they gave me.  
              [shows small test tube]

Op: No, not like that! Bigger, like this. [holds up worm habitat]

Teacher: So then I asked them for a bigger one and they gave me this.
              [shows largest test tube]

D: Huh? 

L: It [indicates worm habitat] isn't a test tube. It's a measuring cup because it has numbers on the side!

We head to the Science Cottage in order to get the right materials (and make a stop along the way to write an apology note...

                                                                                    ...after breaking one of the test tubes). 

Op. finds what we are looking for in the kitchen, and Dan and Kara helps us notice all of the different sizes to choose from. 

"We need one with 500."
Five hundred what? 
Are you looking at the M and the L and thinking about what that stands for? 

Dan brings us a beaker full of water. 
We begin to mess about. 

"This [the beaker] is five hundred too!"

"It's at exactly 100." 
What if I tip it this way? Is it less than 100 now?
"No, it just looks like it is."
"Because it's tipping."
So when scientists measure, they look at the water on the table so that it's level. 

"I wanna drop this eraser in."
What's your theory about what will happen?
"The water will go up."

"How much water do we have altogether?"

 "600 and a half!" 
600 and halfway to 700?

[The water in Op.'s the graduated cylinder reaches to an unlabeled mark--one mark less than 100ml.]
How much water do you have?
"A little bit less than 100."
But how much less?
"A little bit."
[Op. grabs a smaller graduated cylinder--on which every count of 10 is labelled--and pours its contents into the larger one. The water now reaches to the 100 mark.]
Now it reaches 100! How much did you pour in?
"It was 90 before because that's 10 less than 100. And there was 10 in the smaller one."
So from one mark to the next on this larger one is 10?

When it's time to head back to the classroom, none of us want our messing about to end. 
Dan, Kara and I agree--what an amazing way to come to a genuine understanding of scientific tools. 

Without direct instruction, the boys have come to understand that:
-The amount of water stays the same no matter what size cylinder it's in.
-The measurement of water changes when something is dropped into it. 
-The width of a cylinder, and not just its height, contribute to how much it can hold. 

They have figured out so much, just by being given time and trust. 

-Posted by Mauren Campbell 

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