Floating numbers

Floating point numbers (float and double) are stored in a different way to integers.

The details are complex but the format is known as IEC 60559 and details of this can be found here:

http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=57469

There are several ways to show what the individual bytes (and hence bits) of a float or double are. I can show you how to do this if you want though I doubt whether you'll find the details very useful.

To understand the 'decimal' type, it's necessary to review some history.

In COM and VB4/5/6 programming, there was an 8 byte data type known as Currency which (IIRC) was accurate to 4 d.p.

This wasn't sufficiently accurate for many purposes and a 16 byte Decimal type was introduced as well (accurate to 28 d.p.) though only as one of the sub-types of the Variant type. The name was probably chosen for lack of a better one!

When .NET came along, it was decided to standardize on the Decimal type (decimal in C#) and the Currency type wasn't therefore brought across as one of the standard types (it should have been IMO but there we are).