Dr. Aryn Pyke (Pike), a graduate of Cognitive Science (Ph.D. 2009) recently published an interesting paper with co-authors John Anderson and Jon Fincham in which they used a unique combination of brain scanning and modelling to show the stages of mental processing for math problems.

http://www.psychologicalscience.org/idex.php/news/releases/distinct-stages-of-thinking-revealed-by-brain-activity-patterns.html

Here is the link of Dr. Aryn Pyke’s interview on National Public Radio:
http://wesa.fm/post/cmu-maps-your-brain-math#stream/0

Here is the link of  Dr. John R. Anderson’s (co-author of the study),  interview with the New York Times.
http://www.nytimes.com/2016/07/29/science/brain-scans-math.html?_r=0