Saturday, September 17, 2011

Fractions Manipulatives

Although I have always used paper cut-outs for exploring fractions, there is something to be said for having something that is a bit more durable in a manipulative.  One of my friends suggested cutting out foam sheets from a dollar store.  I was very happy with the results.


At first, since I didn't have a geometry set, I simply traced a container lid and folded to get halves, thirds, sixths, quarters, and eighths.  The fraction pieces were pretty accurate, with careful folding.  And there is something to be learned from having the kids do some of the folding and cutting. 

Still, having the right tools makes a difference in the "cleanness" of the edges and, in the end, is still more precise.
I used a radius of approximately 5 cm for all of the circles, and a pencil (not shown) to draw in the edges for cutting, before labelling each fraction piece. 

With $2, I made 2 sets of
  • 1 whole,
  • 2 halves,
  • 3 thirds,
  • 4 quarters,
  • 6 sixths,
  • 8 eighths, and
  • 12 twelfths.
Spidergirl messed around with putting them together to make wholes for a few minutes before getting
down to some serious play.  We played 'Bakery', in which customers order whole pies made of different flavours.  For example, the photo about would be 1/2 blueberry pie, 1/3 lemon pie, and 1/6 pecan pie.  It would be served as a whole.  At first, I was the baker, then SpiderGirl took a turn to 'bake.'  As she got the hang of it, I would start to replace the number in the final piece with 'the rest,' and she would have to figure out what fraction fit.  If it was wrong, I might tell her that it didn't fit in the pie pan, or that there wasn't enough pie. 
On her own, SpiderGirl began comparing fractions by stacking them to match sizes.

BatBoy enjoyed being a customer in the game as well, eating pie Cookie Monster-style.

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