Tuesday, August 23, 2011

Magic Expanding Chelonian - Day 3

Here is a compilation of images over the 3 days. The scale was preserved by using the Day 0 chelonian as a reference.  So the question: How valid was the claim it would grow 600%?  Do I need to go back to the $2 shop and demand my money back? Keen to see what my Year 9 maths class makes of this one....

Click for a full size image

Actually - they won't be getting this ready-to-go picture - that's way too easy. Instead they will be offered 4 raw photos of each day, each picture with a Day 0 turtle for scale reference, as well as access to some real-life expanded chelonians if they want to try some hands-on physical measurements.  If this activity works, I might go out and buy another 15 chelonians.





3 comments:

  1. very cool, thanks for the great graphic. I would say they're claim is not that far off. I read the original as being 7x7 boxes. To grow 600% means to get to 7x the size, right? That means that any linear dimension needs to grow to 7x7^(1/3)=13.4 boxes. I read the biggest to be roughly 11x12 boxes which is close. From a percentage perspective, it's interesting that 11 boxes means only a 288% growth and 12 boxes means a 504% growth. I think it comes down to the uncertainty on the "600% growth" claim. Significant figures (ugh, blah, ugh, yuck - sorry, I hate using those) would suggest that the 6 is uncertain. Mostly I'm curious to hear how many of your students fixate on the linear dimensions instead of the volume as I've done. What do you think will happen?

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  2. I'm thinking the 600% is good too - if it means volume - which is reasonable. Funny - I just had a debate with someone if 600% means 7x growth or 6x - I'm arguing it means 7. I like your observation about significant figures - my Year 9 did significant figures earlier in the year - be interesting to see what comes up in the discussions.

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  3. I'm not predicting anything except a few will be confirmed in their belief they have a v strange teacher - another 'weird activity' :-) I love it!

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