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# This isn't Math!

### #1

Posted 17 July 2013 - 08:15 PM

Sometimes, I find, math students get obsessed with numbers. So an exercise that I often assign the class is a geometric measurement problem. I assign each student in the class an identical solid rectangular prism and a string (that is randomly cut so that no student is guaranteed the same size string but each string is longer than the biggest length of the prism). The students are then challenged to come up with a method without the use of pencil and paper to find the measurement of two opposing corners of the prism like in the picture below. Remember the rectangular prisms are solid so a direct link is impossible. The students may share supplies in order to complete this calculation.

What is the least amount of student supplies needed to complete this calculation?

### #2

Posted 17 July 2013 - 09:12 PM

### #3

Posted 17 July 2013 - 09:55 PM

### #4

Posted 17 July 2013 - 10:09 PM

### #5

Posted 17 July 2013 - 10:24 PM Best Answer

### #6

Posted 17 July 2013 - 10:36 PM

Spoiler for

no markers of any sort. you are on the right track with this solution but there is a more efficient (less material needed) solution

### #7

Posted 17 July 2013 - 10:47 PM

### #8

Posted 17 July 2013 - 11:00 PM

essentially the removal of the 4th block in Dege's answer is equivalent to K-man's

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