# Working With Floating Point

Some RETRO systems include support for floating point numbers.
When present, this is built over the system `libm` using the
C `double` type.

Floating point values are typically 64 bit IEEE 754 double
precision (1 bit for the sign, 11 bits for the exponent, and
the remaining 52 bits for the value), i.e. 15 decimal digits
of precision.

## Prefix

Floating point numbers start with a `.`

Examples:

   Token    Value
    .1       1.0
    .0.5     0.5
    .-.4    -0.4
    .1.3     1.3