Khan/khan-exercises — pull request #45811 by hirshjain32 (2013-05-14 02:39:15+00:00)
Title: Edits to "Adding and Subtracting Fractions" - 2

-Adds color
-Reduces fractions as a first step, so that smaller numbers are being dealt with
-Adds short descriptions of how denominator is found and how fractions are simplified