Sunday, May 26, 2013

Estimating Centimeters Road Work

And on the second day, we made businesses. There was KFC, and a dentist, and a mall. And it was good. Sounds slightly biblical...
But anyhow- my kids are obsessed with making milk carton buildings.  They are now even collecting other sorts of containers to have different shaped buildings.  Which is great, as I get to review my economics teaching from the beginning of the year, and they are happy as clams.
Keeping this in line with my math instruction however, we continued our estimation with centimeters investigation by deciding to lay down some asphalt.  We're city kids, after all.  We need our pavement...
So we started with looking a the lake here in Super Mooseville.  We wanted a road that circled around it.  How many centimeters did we think that would be?  Our first hiccup was getting ourselves out of the habit of thinking about how many of our rulers would fit around the lake.  I crumbled a bit under the shouts of "FIVE!", "No! Eight!!!".
But once I was able to redirect- "Ok, if you think it is seven rulers, how many centimeters is that?"  And the work began.  We divided up into teams and first had to make an estimate WITHOUT putting our ruler on the map, and report back our decision so it could be reported and we could receive our asphalt (black construction paper).
They tried to get as close as the could to the map without actually laying their ruler down on it.  We came close to cheating a number of times and had to be reprimanded by the mayor.
Now, I still had folks come back to me with the answer "Seven." And I redirected, paused and talked about adding over and over again (a slight introduction to multiplication, if I do say so myself).  Most of us had 12 centimeter rulers, so we talked about adding the number twelve over and over.  Of course, this discussion led to everybody picking the same estimate of seven rulers- but regardless, they had to practice some addition skills.  Here's two different teams strategies:

So all of the teams came back with the estimate of 84 centimeters. Hey- they added correctly, so awesome sauce!  I gave them their paper with the directive that they had to cut 2cm wide strips and measure them out 84 cm long.  Also a good exercise.  Some of them fell apart on the practical application portion.  But mistakes are good in this sort of math- because I could see WHO wasn't getting it, and get over there and do a mini-tutorial.
At last, we had our strips.  Since everyone had the same amount, I just picked a random team and laid down the 84 centimeters.  It got about half way around our lake.

Another excellent math moment, but we got to talk about what one half meant and the idea of doubling.  How much more asphalt did they need?  Like our investigation into color tiles/inches/height, we were able to take our initial estimation based on visual perspective, and then accentuate it with some hard data.  What are we learning at this moment? 84 seemed like such a big number, but we hadn't really visualized properly that centimeters are a small measurement.  84 inches probably would have been about right in this case, and this also lead us to realize that  it was just a little more than two centimeters that made an inch, since we made it half way around the lake.  You can't get this sort of discovery done measuring a crayon and a tissue box!
So we went back into our teams and started to measure out our road again.
This team decided to try to connect their rulers end to end.

 This team measured one strip, and then tried to add on that number over and over each time the put a new strip down.  Challenging for them, and they didn't get the right number, but it was great to see them take that risk.

It turned out that it took 163 centimeters to get around the lake.  Phase two begins: How much road to go around the outer loop of town?  This time, we skipped the visual perspective step and laid down the 163 cm of road we had.  We got almost back to the lake.  So it was easier for them to see, how much more road did they need?

Town still in progress.  More posts to come!

In the meantime, as you wait on the edge of your seat for more- head on over to see Crystal at

My KinderGarden
and sign up for her second giveaway with tons of cool prizes including winner's choice from our shop The Meek Moose!  Here's the rafflecopter link:

Be safe everybody!

1 comment:

  1. What fun and what learning! It looks like some significant ownership and engagement. I am curious about measuring with cm not inches. We do cm in Canada (legally we use the metric system, but for so many things we still use imperial measurement in real life - it is now part of the Canadian psyche that we are measurement bilingual!), but I thought Americans were true red white and blue imperial.

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