## Bug #13754

Updated by lionel_perrin (Lionel PERRIN) about 4 years ago

Hello, I'm not sure if I've misunderstood the bigdecimal class but in the following example, I only get 12 significant digits using bigdecimal while using Float, I get a correct value with 17 significant digits. ~~~ ruby # using floats 101/0.9163472602589686 # 110.22022368622177 (OK: floating point computation) # using bigdecimal a = BigDecimal('101'); a.precs # [9, 18] b = BigDecimal('0.9163472602589686'); b.precs # [18, 27] c = a/b; c.precs # [18, 36] (OK: I understand that c is computed with 18 significant digits) c.to_s # "0.110220223686e3" (Mmm: I see only 12 significant digits) c - BigDecimal('0.110220223686e3') # 0.0 (Looks like c only stores 12 significant digits and not 18) ~~~ Using the Rational class, I've seen that the value I'm expecting is about: ~~~ ruby BigDecimal.new(Rational(101/Rational('0.9163472602589686')), 18) # 0.110220223686221775e3 ~~~ 110.2202236862217746799312