Elementary Data Types - Floating-Point Numbers
 
QuickBASIC uses IEEE-format floating-point numbers rather than the Microsoft
Binary format used in earlier versions. IEEE format gives more accurate
results and makes it possible to use a math coprocessor (for example,
an 8087, 80287, or 80387).
 
Floating-point values are represented in a different format from integers.
Each floating-point value consists of three parts: the sign, the exponent,
and the mantissa.
 
In a single-precision number, the sign takes 1 bit, the exponent takes
8 bits, and the mantissa uses the remaining 23 bits and an additional
implied bit. Double-precision values occupy eight bytes or 64 bits:
1 bit for the sign, 11 bits for the exponent, and an implied bit and
52 actual bits for the mantissa.