My Yr 12 class arrived this morning asking whether we would
be doing a Quibans based on the Referendum result. Here is what we did.
They knew that the country had voted as follows:
Leave – 52%
Remain – 48%
They told me the turnout was 72%
I had looked up the total number of people who voted and
wrote that up: 33,551,983.
The questions they decided on were:
- How many people voted Leave/Remain?
- What proportion of the population of the UK voted?
- How many eligible voters didn’t vote?
Instead of them giving me answers verbally, we set up a
spreadsheet on the board and they came up in turn to do some typing. This allowed us to talk about how to
structure this sort of thing on Excel, and what they should type. It also helped us explore the difference
between typing the number 52 and treating it as a percentage (dividing by 100
when we used it) and typing 52%, which Excel treats as the decimal 0.52
After that I gave them figures for South Cambs (where my
school is):
Leave – 39.8%
Remain – 60.2%
93,189 people voted.
They worked out the number who voted to remain/leave:
They pointed out that these can’t be exact because you can’t
have 0.78 of a vote. I then told them
the actual figures (shown above).
First they worked out the accurate percentages, and found
that they had been correctly rounded to 1dp here. This then led to the use of the upper and
lower bounds to determine how many people might have voted each way.
Clearly, if the figures for South Cambs ended up being
approximate because of rounding issues, then the national figures might also be
approximate, so we worked out upper and lower bounds for those.
So: we did lots of good percentages work (including inverse
percentage to calculate the total number of eligible voters), used
spreadsheets, considered upper and lower bounds. Lots of interesting things.
At the very end of the lesson one student was interested in
whether the margin of victory was big or not.
Is 52% to 48% a 4% difference, or is it a 2% difference? Or should you look at the raw figures (1.3
million is a big difference).
Here are some of the links we used:
