> the very earliest iterations of Windows Calculator, starting in 1989, didn't use the rational arithmetic library, instead using floating point arithmetic and

> the very earliest iterations of Windows Calculator, starting in 1989, didn't use the rational arithmetic library, instead using floating point arithmetic and the much greater loss of precision this implies. As I recall, there was quite a bruhaha about Windows calculator solving 2 x 2 as 3.9999999945 or something like that. Pretty sure this rational number library was added in response to bad press.