I was examining a slope map that I created in ArcMap 10.1 approximately a year ago. Calculating the same slope map in ArcMap 10.3 gives me slightly different results. Did something change in the way slope is calculated? I used the same 100m DEM one year ago as I have today. Also, I noticed that the 10.1 slope map opens in a stretched B&W symbology while the 10.3 slope map opens in a classified symbology. Screenshots below show the slightly different results including an increase in the maximum slope value.