Three halves make a whole?

Our Prime Minister, David Cameron, came in for some criticism this year for his use of the word 'half', when, in answer to a question about what were the Houses of Parliament like, he replied, 'half museum, half chapel, half school'. 'You can't have three halves!' was the outcry.

Obviously, what he said is not intended to be an exact statement of proportions, but even so this looks as sloppy as the often-heard 'I'll have the bigger half'.

However, on reflection, Cameron is OK in what he says here. You can have three halves of a set, for example, if the halves overlap. For example, a teacher could say, half of the children in my class are Asian, half of them are male, and half of them walk to school.

So, if, we were to assume that there are 100 quintessential qualities or features that characterise the Houses of Parliament, it is quite possible that 50 of these are shared with those of a museum, 50 of them are shared with those of a chapel, and 50 of them are shared with those of a school. This is because the quintessential qualities of museums, chapels and schools are not unique to each of these kinds of places.

So, it seems alright to say that Parliament feels like half museum, half chapel and half school!

There! It's not often you get me supporting our Prime Minister; but fair's fair.