Uses of Class
java.lang.Number

Packages that use Number 
Package Description
java.awt
Contains all of the classes for creating user interfaces and for painting graphics and images.
java.lang
Provides classes that are fundamental to the design of the Java programming language.
java.math
Provides classes for performing arbitrary-precision integer arithmetic (BigInteger) and arbitrary-precision decimal arithmetic (BigDecimal).
java.text
Provides classes and interfaces for handling text, dates, numbers, and messages in a manner independent of natural languages.
java.util.concurrent.atomic
A small toolkit of classes that support lock-free thread-safe programming on single variables.
javax.accessibility
Defines a contract between user-interface components and an assistive technology that provides access to those components.
javax.management
Provides the core classes for the Java Management Extensions.
javax.management.monitor
Provides the definition of the monitor classes.
javax.swing
Provides a set of "lightweight" (all-Java language) components that, to the maximum degree possible, work the same on all platforms.
javax.xml.datatype
Defines XML/Java Type Mappings.