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.

Magic Expanding Chelonian - Day 1

This magic expanding chelonian is turning out to be even more fun than I expected.... although it is kind of sad what a math teacher does for kicks on Saturday night...

Download GeoGebra file 

I'm guessing the promised 600% growth in 72 hours will be by area - or maybe even by volume. I'm getting scared ....

WCYDWT? Magic Expandable Chelonian

What can you do with this?

The Magic Expandable Chelonian : Grows 600%!
(Do not swallow!)

Yes - it's fun AND educational too!

My head is spinning with possibilities!  I'm very curious to see the questions my different maths classes ask. I bought three of these today at the $2 shop - the plan is to show the class the original packet then see what happens. I'm hoping to try out some version of Dan Meyer's WCYDWT rubric and half way through the period bring out some turtles "I expanded earlier". The packaging suggests dramatic growth in 48 and 72 hours - so I'll get some going a few days earlier.

It's fun and educational - or so the packaging claims. To be honest, I don't even mind if it's not educational - I just want to see what happens to the turtle! And what would happen if I did swallow the turtle and then drank a litre of water?

Next in this series: The Magic Expanding Chelonian - Day 1