Two problems from a Christopher Danielson paper

A discussion on Twitter about yesterday’s project:

A really neat conjecture shared by Tracy Johnston Zager

led to this paper from Christopher Danielson getting posted in a thread (the direct link to the paper is in the bottom tweet):

I’m terrible at evaluating the difficulty that kids will have with various math problems, but the two problems at the beginning of the paper looked interesting so I thought I’d give them a try.

The first problem is about determining the largest rectangle (out of 5 choices) with a fixed perimeter, and the second problem asks you to find the perimeter of a region with an unusual shape. Here are each kid’s response to the questions. This was nice exercise – the kids had some pretty interesting thoughts:

Question 1

Older son:

Younger son:

Question 2

Older son:

Younger son: