Definition: floating point

A method for storing and calculating numbers in which the decimal points do not line up as in fixed point numbers. The significant digits are stored as a unit called the "mantissa," and the location of the radix point (decimal point in base 10) is stored in a separate unit called the "exponent." Floating point methods are used for calculating a large range of numbers quickly.

Floating point operations can be implemented in software or in a floating point unit (FPU), which may be a separate "math coprocessor" chip or a circuit in the CPU. See math coprocessor, binary numbers and NaN.

  FLOATING POINT EXAMPLES

  Mantissa  Exponent  Value

    71        0         71
    71        1        710
    71        2       7100
    71       -1          7.1

How Numbers Are Stored

There are four ways numbers are stored in the computer, and this example shows each of them containing the decimal number 7100.