integers with operations of addition,
subtraction, multiplication; see the examples of big
integers
integers under modular arithmetic
where m is a positive integer
rational numbers with operations of
addition, subtraction, multiplication and division; see the
examples of rational numbers
Gaussian
integers, i.e., complex numbers which have integer real and
imaginary parts; see the complex numbers examples
algebraic extension
field; the algebraic number 
is defined by the
polynomial 
with integer coefficients which can be
represented precisely; the algebraic number is a
root of the polynomial , e.g., 
is represented by the polynomial 
and
the algebraic number 
could be defined by the
polynomial 
; see the examples of
algebraic numbers
floating point numbers with a
precision of 
decimal digits where
is an arbitrary positive integer--it can be 
or
; see the examples of big floating
point numbers