# ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-linux]
require 'bigdecimal'

10000.times do
  b = BigDecimal.new(1000+Random.rand(5000)) / 100
  # b.class => BigDecimal
  (b**0.75).floor # _sometimes_ raises TypeError: #<Class:0x000000277a3a38> can't be coerced into BigDecimal
end