As the one who started the duplicate on that close vote I wish to draw your attention to:
Why is BigDecimal the best type? I don't understand the relevance of arguments such as precise calculations or people with large net worth. I am pretty sure that there are no currencies that round to the 10th decimal place, and almost no one has 8-bytes worth of money (if it were to store it as a long).
For taxes and other intermediary calculations, I can see how it is important to make sure you are using a proper type that doesn't round/truncate values prematurely, but that doesn't seem relevant to me either since an error of 0.0000000001 cents on the dollar does not seem that big to me.
It may be due to my lack of understanding of the importance of accuracy when it comes to financial statements, so perhaps someone can also clarify whether a millionth of a cent is significant as a final number.
This is the question.
In the question it was duped to:
I can't imagine that last digit being much of a problem in real life. For example, if I ask for a "0.30000000000000004 meter metal rod", I'm not going to later complain that "this rod is 0.00000000000000004 meters too long!" (I can just cut the extra off, right? :)
In my reading, these are the same question worded differently. The origin refers to currency, the dup target is one that deals with currency and the broader issue of floating point inaccuracy.
The answers in the duped question directly answer the "an error of 0.0000000001 cents on the dollar does not seem that big to me." portion