There follows a description of IEEE and IBM 370 floating point formats. This information should be of no use whatsoever to the average user, and is not even guaranteed to be correct, although corrections are welcome. There is a sign, a mantissa, and an exponent. The leading 1 of the mantissa is suppressed. The mantissa may have up to 3 leading zeros, even when normalised.
Denormalised values are valid.
Errors can build up rapidly under the former scheme. University of Cambridge HPCF, October 1997.