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Unit study that will cover area and volume?


Moonhawk
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We are having some issues with remembering LWH for volume (rectangular) and LW for area. And also LW/2 for triangles. I'm trying to think of a unit study that can help go over this information and also incorporate other topics, hoping it may stick better if it's linked to other contexts. I'm probably too tired right now because nothing comes to mind. Square cakes? Any help appreciated. Thanks! 

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11 hours ago, square_25 said:

 

Not a unit study, but I think playing with blocks and explaining where the formulas come from helps the most.

This is how we typically do things (Math U See) and it's worked for everything. Except this. Which is slightly ironic to me because it is the most literal of the things to be shown with blocks, right??  And she gets it at the time, "Oh, that makes sense, I remember this!" and can run through problems for a few days with no issue, but then a week later on a general review of everything it's loosened, and we are having to take time again. I'm hoping that something more ... hands on? or less familiar? than the blocks will stick better.

Edited by Moonhawk
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 Yes, she can do these. And not just by counting, lol. I did a quick thing with her before bed: she did these okay. We did review on Monday so it seems to still have stuck since then this time. But I didn't mix it with volumes and perimeters and triangles. 

eta Oops forgot to quote, paging @square_25 so you see this

Edited by Moonhawk
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On 4/1/2019 at 7:34 AM, square_25 said:

 

Great! That's a relief. 

I wonder if this is just too much stuff in one go, conceptually? Like, conceptually, area and perimeter and volume... they are all different ideas, and maybe mixing them all together is confusing. And then you have to calculate them all in different ways... are they only doing right triangles or all triangles? Are the supposed to think of a triangle as half of a rectangle or just memorize the formula? 

I might just do perimeters and areas on shapes like the ones above for a bit, and throw in rectangles or rectangles missing a corner square or whatever in the mix. They are easy, and if you forget the formula, you can just solve it by counting, which I think encourages confidence :-). Then once the idea that "area is stuff inside the shape, perimeter is length of the outside" is totally solid, I'd do triangles as halves of rectangles. 

I'm not familiar with Math-U-See, so I don't know their sequence... but I do find that starting with things that don't have a formula and just test the concept can be valuable for kids. It feels less like a memorization when it's simply a trick you've seen already for a specific kind of shape.  But I'm not sure what order Math-U-See covers it in: do you happen to have a link? 

 

I do think for her it's just too much at once and she confuses herself once she sees things close together. Definitely it's all concept before formula, I know they KNOW the formula but it wasn't something I had them write down 10 times or anything like that. Both concept and formula seem to go out the window once she sees two different concepts close together. She can do the first one fine whatever it is, but the second brings up a deer in headlights. (Son doesn't have this issue.)

I don't have the sequence, sorry; this is all actually review since this is something we did last year (or the year before??) and that is just brought up on review pages. And then I add in extra ones once I saw it wasn't sticking anymore. 

Anyway, we're going to try baking a square layer cake, making a grid with icing, maybe different color for perimeter, etc. Get them to write out a paper with pictures or something. IDK. Maybe eating it will help it absorb? haha...

I liked the idea of building/decorating houses, but I'm not ready to unbox that Pandora until the summer, lol.

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Sometimes visual reminders help. We have this up in our school space. Or, at least, we used to. BalletBoy stole it at some point this year - took the frame right off the wall. I think it's in his room...

https://www.etsy.com/listing/196581344/geometric-formulas-fine-art-print-by?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=math+poster&ref=sc_gallery-1-1&plkey=0e5ee4e80a2d4bf62d5a02381b204584340ac4e0%3A196581344&frs=1

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On 4/3/2019 at 6:01 AM, square_25 said:

 

I've actually seen this a lot. Probably more than half of my AoPS kids can only do about one thoroughly new concept per lecture (and lectures are once a week), and they are fairly strong students. New concepts are tricky! 

What I was suggesting was to make sure the idea bakes in before doing rectangles: so doing perimeter and area on a square grid, like the ones I drew, for a few weeks. That gives kids confidence they know what are and perimeter are and primes them for the formula. Plus if they forget the formula they can figure it out again themselves or just count if need be. 

I can draw you some more shapes, if you like, to show what I mean. Would that be helpful or not? 🙂

Thanks for the suggestion! No need for more drawings, I got the gist, thank you for the offer 🙂

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