Number systems include the familiar integers, rationals, reals, etc. as well
as unusual extensions of these sets such as p-adic and hyperreal numbers.

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### Internet references

Wikipedia: Number
system

Fact archive:
Number
system

### Related pages in this website

Construction -- Construction of sets
of numbers, starting with the original Peano Axioms, formulated so that zero *is*
included in the set of natural numbers. (See Is
Zero a Natural Number?)

The webmaster and author of this Math Help site is
Graeme McRae.