The Outputs tab contains the list of the output parameters from the Web Service, and allows you to specify target dataslots for each value. In the MathService case, the Outputs tab contains the "AddResult" parameter, containing the sum of the A and B parameters.
Here, we mapped the AddResult so the value from the addition is stored in the Z dataslot.
Notice that the dataslot data types are not mentioned anywhere in the mapper. In case the type of a dataslot does not match the type of an input or output, the managed adapter framework converts the value appropriately. Not all such conversions may make sense in the context of a given Web Service or Business Process Server process, so be careful when mapping different types, and consult the information in the "Supported Types for Conversion" table in the "Developing Custom Managed Adapters" chapter in the Customization Guide.