Available with 3D Analyst license.
The Raster Math tools apply a mathematical function the input raster or rasters.
The arithmetic tools perform addition (Plus), subtraction (Minus), multiplication (Times), and division (Divide) between two inputs. The inputs can be rasters or numbers (as constant value rasters).
The remaining tools apply only to a single input raster and will either convert a floating-point raster to integer (Int) or an integer raster to floating point (Float).
Divides the values of two rasters on a cell-by-cell basis.
Converts each cell value of a raster into a floating-point representation.
Converts each cell value of a raster to an integer by truncation.
Subtracts the value of the second input raster from the value of the first input raster on a cell-by-cell basis.
Adds (sums) the values of two rasters on a cell-by-cell basis.
Multiplies the values of two rasters on a cell-by-cell basis.
A more comprehensive range of mathematical calculations (trigonometric, exponential, logical, and so forth) is available with the ArcGIS Spatial Analyst extension license.