Issue #10850 has been reported by Elyasin Shaladi.
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Bug #10850: BigDecimal division incorrect
https://bugs.ruby-lang.org/issues/10850
* Author: Elyasin Shaladi
* Status: Open
* Priority: High
* Assignee: ruby-core
* ruby -v: ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
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I tried this in Ruby 2.1.4, 2.1.5 and 2.2.0, but in none of the versions it seems correct to me.
irb(main):041:0* amount1 = BigDecimal("241.3")
=> #<BigDecimal:7f49bcb03558,'0.2413E3',18(18)>
irb(main):042:0> amount2 = BigDecimal("1800")
=> #<BigDecimal:7f49bcaf3400,'0.18E4',9(18)>
irb(main):043:0> rate = amount1 / amount2
=> #<BigDecimal:7f49bcae8398,'0.1340555555 5555555555 5555556E0',27(45)>
irb(main):044:0> rate * amount2 #should return amount1 = 241.3 in BigDecimal, but it does not
=> #<BigDecimal:7f49bcad6a30,'0.2413000000 0000000000 00000008E3',36(45)>
My guess is that there is a bug in the BigDecimal implementation.
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https://bugs.ruby-lang.org/