Khan/khan-exercises — pull request #5502 by smenks13 (2011-11-03 16:50:55+00:00)
Title: Fix exercise: Adding and subtracting radicals - Issues #5453 #5476

Added a new problem type to house the zeroes. Users don't see a radical, and just have to input 0. Might be a giveaway when they see the different answer type, not sure how to do it otherwise though.