sqlite3 Float issue

I'm submitting this for help collaborating on what should be done, if anything.

Example of the issue

Here, I am summing -40.25, 100, and -34.59 in the database:

irb(main):001:0> my_envelope.bank_transactions.sum(:amount)
=> #<BigDecimal:1011be570,'0.2515999999 9999997E2',27(27)>

The sqlite3 methods for retrieving this data from the row returns a double. This means that we're dealing with normal Float precision issues from the moment it comes out of the database. Then, since the column type is decimal, rails converts the number from Float to BigDecimal. Before Ruby 1.9, Ruby would have rounded this number to 25.16 and then we would see the correct number in the BigDecimal.

My issue with this is that I think we can assume that people should know about precision problems with a Float, but when Rails hands them a BigDecimal, I think they should be confident that it represents the actual number.

What do we do?

Would it be a good idea to round these numbers for the user before we send it to them as a BigDecimal? We could even just call BigDecimal.round(12) to round to the 12th decimal place or something. Any thoughts?