We have been busy scientists lately in Rm. 202. Let me tell you about it! (And also let me apologize for not writing about Science very often. This may be one of the first posts I’ve ever included about our lives as scientists…boo. 😦 )
During 3rd quarter we were busy learning about many things. The latest science unit we ventured through was one on Living Systems, specifically animal classification.
One thing we focused on was dichotomous keys. What? You’ve never heard of them? Well before I started teaching about them in 4th grade several years ago, I hadn’t either! Well at least I didn’t know that’s what they were called. Let me show you what I mean:
The goal is for students to be able to use keys like this to identify animals, but we started somewhere else. With shoes. We worked first to CREATE a dichotomous key, so we’d know how it works, and then we practiced using it.
We began by putting everyone’s shoes in a big pile on the floor. Then, we had to decide two groups that we could classify all those shoes into (see, the dichotomy part–two groups). Here’s how we started:
Then, with two groups, we tackled the “boots” pile first. Again, we asked ourselves what two groups we could make. This was pretty easy, and so we decided on:
Next we had a big ‘ole pile of everyone else’ shoes to classify. We started like this:
After that pile was classified and labeled, we could tackle the other side of the “not boots” bunch, which was colored shoelaces.
And so once we were finished, our key looked like a beautiful tree, and ended with everyone’s names. We could now use that key to determine whose shoe was whose.
Here is Natalie in action, proving how she knows who shoe she has in her hand:
After we had practiced with this dichotomous key that we built, kiddos had a go at the one from the top up there, where they had to identify the silly scientific names of these common items:
1. a die
2. a small paperclip
3. a large paperclip
4. a piece of chalk
5. a popsicle stick
6. a colored marble
7. a white marble
8. a sharpened pencil
9. an unsharpened pencil
10. an eraser
Could you do it? Use this dichotomous key and tell us what you think the names of each of these items are. Good luck!