Friday, February 3, 2012

Math and applied imagination

Shannon had an odd assignment yesterday. She's reading The BFG, by Roald Dahl, and in it, a 24-foot giant is the main character. (he's a puny wimp compared to the 50-foot giants he lives with, but that's beside the point) Her worksheet yesterday involved having her step into one of the scenes from the book and pretend that she's hosting the giant for a visit. The giant is four times as large as a normal 6-foot man, so most of the things he'll need will also need to be multiplied by four.... how long should his bed be? What would you give him for a pillow, and how big will it be? She was supposed to take most things that she'd need, multiply them by four, and give the answer. She had no problems doing that for straight measuring stuff. But then it went on to talk about how much the giant would eat, and assumed the child would do the same thing. How many slices of pizza? How big a glass of milk? I had told her to use her imagination and pretend she was really hosting the giant for a few days. Luckily, she talked through her answers as she filled out the worksheet.

You see, just because a giant is four times as tall, does not mean he's going to eat four times as much. He'll probably eat a lot more than that. We had JUST covered doubling area and perimeters in math in the previous few days. She quickly caught on as a given that in order to double a rectangle's area, you only double one dimension, NOT both. So she instinctively took that knowledge to this literature assignment. It was quite obvious to her that 4 slices of toast would not be enough, even if 1 slice of toast would be OK for her. She felt the giant would drink 5 gallons of milk even if she can't drink a gallon. The square-cube law is totally instinctive for her, and you know what? She's right. She also used the logic that the giant had been eating snozzcumbers most of his life, and would probably love real food so much that he'd pig out and eat even MORE than he would "normally." And you know what? She's probably right there, too. She even went so far as to answer the last question the following way: "How much popcorn would the giant need?" "This is getting way too spendy, he doesn't need any."  I loved it.

So, because she answered (almost) all her questions in complete sentences and walked me through the logic she used, I decided not to "correct" her work and scold her for not simply deciding a "normal" amount and multiplying by four. Sometimes, the joy of homeschooling is combining topics and showing children that math doesn't just live in a mathbook. But sometimes, it's also OK to live in the moment and not require everything to be just so.

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