Why aren't large numbers limited to 64 bit values?

[Geoff Canyon]

On Thu, Dec 10, 2015 at 1:17 PM, Bob Sneidar <bobsneidar at iotecdigital.com>
wrote:

> Because the binary equivalent of a 40 digit decimal number is NOT 40 bits.
> It is many more bits. For example the binary equivalent of
> 10000000000000000 (17 digits) is 101111101011110000100000000 (27 digits).
> You are thinking of each decimal digit as a binary bit.


​It wasn't that I was thinking of 64 bit as meaning 64 (decimal) digits and
wondering why the value wasn't exact, it was that I knew the value was
(much) greater than 64 bit, and wondering why it was accurate at all.​