I read this in the tutorial on this site about floating point variables but It doesn't make much sense.

**Byte 1: Exponent**

This holds the exponent of the object. The byte is treated as a signed 8-bit integer, except in a strange fashion. $80 is zero, $81-$FF are positive exponents ($81 = 1, $FF = 127), and $00-$7F are negative exponents ($00 = -128, $7F = -1).

What is the use of this exponent ? I do not really understand it.

And then after that I read this:

**Byte 2-8: Data**

The rest of the bytes are used to hold the data. Each nibble represents the "decimal" digit. The value is treated in scientific notation.

Ex.: $00,$80,$31,$41,$59,$26,$54,$00 represents a real value 3.14159265400

i do not understand how a hexadecimal number can represent a decimal digit. And in the example given We only get 8 bytes which does not make sense since there should be 9. First I thought byte 0 was omitted but it isn't.