Sum of Multiple Polygon Shapfiles

Discussion created by gilster on Jan 31, 2012
Latest reply on Jan 31, 2012 by tereshenkov
This seems like such a basic idea, but I have yet to figure it out. I have 3 shapefiles with a similar field named grade. That grade is a value of 1, 2, or 3. I want to make a map showing the values of the area and places where each of those overlap, is the sum of all shapes overlapping that area. Any ideas on how to do this?