_FLOAT
From QB64 Wiki
_FLOAT numerical values offer the maximum floatingpoint decimal precision available using QB64.

Syntax
 DIM variable AS _FLOAT
Description
 QB64 always allocates 32 bytes to store this value.
 It is safe to assume this value is at least as precise as DOUBLE.
 Under the current implementation it is stored in a 10byte floating point variable.
 _FLOAT variables can also use the ## variable name type suffix.
 Values returned may be expressed using exponential or scientific notation using E for SINGLE or D for DOUBLE precision.
 According to IEEE754 this can store a value of up to 1.1897E+4932 compared to a DOUBLE which goes up to 1.7976E+308.
 Floating decimal point numerical values cannot be _UNSIGNED.
 Values can be converted to 32 byte ASCII strings using _MK$ and back with _CV.
 When a variable has not been assigned or has no type suffix, the value defaults to SINGLE.
 Note: OpenGL's _GL_FLOAT constant is a SINGLE (4 byte) floating point number, while a native QB64 _FLOAT is a 10byte floating point number.
See also