Floating point numbers, as well as numbers in scientific notation, consist of four parts:

1. sign of the entire number
2. exponent
3. sign of the exponent
4. mantissa (the fractional part)

The base of the exponent is always fixed. Scientific notation uses 10 as the base. The mantissa in scientific notation is a real number between 1.0 and 10.0, not including 10.0.