Khan/khan-exercises — pull request #44651 by petercollingridge (2013-04-14 21:56:59+00:00)
Title: Reduce number of data-ensure loops and variables

I realise this doesn't achieve much, but it does reduce the number of data-ensure loops and tidies things up a bit. Is there any reason to use `\displaystyle` other than to make the fractions larger?