Fair enough!

We need to be sure that our random flash LED light really is random or else sneaky brained visual cortexes will keep checking over where the light flashes most often, and we need to know if we are going to use it as an electronic dice for gambling of course! (Not encouraged by the 'Out of Sight' Blog or the Royal Society of course).
Lots of us did a tally count test of lots of blinks...

I've put the results in a spreadsheet to make it easier to see :)

Is that what we expect? It is difficult to say exactly - you could just be very lucky and keep rolling sixes even if it is uniformly random, but there is a test you can do which tells you the probability that you would get results this different from the ideal equal proportions of each number - the Chi-squared test. You can see that there is a bigger than 10% chance that our results would be at least this uneven for most individuals and for the combined total - student 6 looks to be a bit odd though... 99.5% probability that data like theirs isn't generated by a fair circuit! Maybe the capacitor was big so their LEDs flashed slowly, and then if they were testing quickly the LEDs selections would not be independent (or maybe they didn't like 5s and cheated?)