If you have Spatial Analyst (SA), there is a tool called raster calculator. You can add it to the SA toolbar and then use it to perform basic raster math such as multiplying a raster by a constant, adding rasters together, preforming if/then functionality on rasters.
Model Builder is included in ArcMap and can be used to put together visual "macro". That is, you can drag and drop data from your mxd and tools from the toolbox into a model. Then, like a flow chart, you can connect them, change settings in the tools, define where you want the output to be saved, and run the model. In multi-step processes it works to both document the process and revise the process if at first you don't succeed.
Hope this helps.