For the preschool set, measurement is important because it integrates a bunch of early math components, and yet it is easy enough for them to do on their own, and is one of those things, like knock-knock jokes, that they seem to happily incorporate into their everyday life so frequently you might wish you had never handed them a ruler. There's counting, obviously, but also the thrills of comparing which helps them understand the importance of the ordinal/relational quality of numbers. The other thing about measuring is that it is so useful in the sort of simple experiments which we do in investigative learning. I've showed them how to measure before, used it in some of our exploratory play, but I had never just talked about measurement in general. And since I love nothing more than a meta investigation, I decided to get them going exploring the idea of precise ways to describe their world.
|Footwear Measurement is vital.|
Printable Rulers, cut out
half sheets of paper folded and stapled to make observation books
stuff to measure!
1. I printed and cut out the rulers- I thought about trying to dig out some wooden rulers, but these were nice because the kids could wrap them around objects.
2. I made them each a book to write down their observations. I've been trying to get them interested in keeping a science journal, but so far they seem to only use them if I make a little mini-book for each project. I hope that this at least will help them get into the habit of recording their observations. Only one kid is ready to start trying to write and sound out words, so I suggested that they draw a picture of the object and write out its measurement in numerals.
3. I set them loose!
|Baby Tiger is 7 inches long- I didn't even need Alex's translation!|
He was stymied by a box that was longer than his ruler. When I asked him if he could think of ways to measure it, he suggested we cut it up and measure the pieces, but was dismayed at the thought of losing the box in the process. I had to hold my tongue not to bring up Schrodinger's Cat which is a bit much even for me to wrap my head around! But the essence of the problem (precise observation altering the subject) seems similar enough that I was tempted! Eventually I showed him how to mark the spot where the ruler ended, measure the remainder and add the measurements together, but he's not quite there yet in terms of comfort with the idea of addition. He was really excited when I did it, though, and went back to measuring smaller things with even greater enthusiasm.
She lost interest pretty quickly, but went back to it after she saw Alex still excited ten minutes later.
She also suggested that we could start measuring our trees, and came up with some interesting ways that we could do so, involving Luke scaling to the top and dropping down a very long measuring tape. I told we could measure how high he goes in them next time he's pruning.
After they spent about 45 minutes measuring things, we watched a clip from Sid the Science Kid about measuring, and we talked about why measuring is important. I framed it in terms of hypothesis testing. Recently we had been talking about plants that could continue to grow in water, like green onions after you cut them, and the kids were insistent that they didn't need soil at all and we could plant a water garden. I told them that I thought they would grow more in the soil, and that only certain plants would grow in the water. To show them how measuring could be used to precisely describe the world, I explained that we could try one onion inside and another outside and observe. They both immediately understood that the bigger one would show whether soil or water was best for the plant's growth, but it was only after I mentioned that there might be very little difference that Anya grabbed her ruler and said we could measure the difference to see even a little change.
This brought to mind our chicken scratch notes on the kitchen doorway showing the kids' heights over time. We marked their heights again, then measured the amount that each had grown since last year, as well as the difference between them. I showed them how to use the metric and imperial units. I think the idea of comparisons over time and between individuals became real to them during this part, which was awesome. I hope that we will be referencing the stuff we learned today in our projects in the future. I also really want to find a kid friendly scale! More dimensions! More measurement!