There is no such thing as a "decimal number". Nor is there such a thing as a "floating number". Those concepts do not exist. I am a mathematician, so I can tell you this with some authority. Those names "decimal" and "floating point" are names of REPRESENTATIONS of numbers. They do not describe numbers themselves.
A decimal representation of a number consists of digits and, possibly one decimal.
A floating point representation consists of a decimal representation followed by a power of 10. For example, 1.325 x 10^7 is a floating point representation that represents the same number as 13,250,000. If you were to multiply that number by 10, you would produce the number that has the floating point representation 1.325 x 10^8.
In a floating point representation, the position of the decimal is flexible. That is why it is called "floating". For example, the following floating point representations all represent the same number:
1.325 x 10^7
13.25 x 10^6
132.5 x 10^5