Tuesday, 24 November 2015

Testing the ancient Chinese dice

In 4G we'd talked about an ancient dice that's just been discovered. What we wanted to know was, would it have been a fair dice? Would there be the same chance of it landing on any face?

Luckily, John Golden had made a net for the dice:
Mr Gregg fixed it so that each hexagon and square had exactly the same area, put on the symbols, and added tabs so we could stick it together:
Now we needed to make them:

Once we'd made it, most of us thought it would be a fair dice, but most of  us weren't sure!
So today each pair of us rolled one fifty times.
Here are the results:
What do you think?
It landed on the red squares a little more than the blue hexagons, but it's very close! Perhaps it's fair...


  1. A&J got much different results than the others. If their data was not included, it looks like the dice are quite fair. SO what is a researcher to do? I suspect that there is something about the way that A&J made their dice that is different from the others, and it would be interesting to see the results if they swapped dice with other students. If the dice that A&J made still comes up with results that are significantly different than the others, well, the question is: who did the truer construction? All the others, or A&J? Lots of good questions to ask here.

  2. Thank you Paula! We'll have a look at that. Also, there are some dice that are really well put together. Maybe we need to test again with those .

  3. Good data eye, Paula! And without that one it's 174-170. Did you happen to collect data on how often the whites came up? That should be double the probability of one hexagon.

  4. Thanks, John. I'm going to have to ask A and J what dice they used. (We ignored the white ones.)