Argh

ruby_float_gotcha.rb

puts a = (2500 * 56) / 10000.0   # => 14.0
puts b = (250 * 5.6) / 100.0     # => 14.0
puts c = 25 * 0.56               # => 14.0

puts a % 1                       # => 0 ... Expected
puts b % 1                       # => 0 ... Expected
puts c % 1                       # => 1.77635683940025e-15 .. Not Expected

guao.

all better!

ruby-1.8.7-p330 :001 > c = 25 * 0.56
=> 14.0
ruby-1.8.7-p330 :002 > c % 1
=> 1.77635683940025e-15
ruby-1.8.7-p330 :003 > class Float; alias :old_mod :%; def %(rhs); old_mod(self + 1 - 1) end end
=> nil
ruby-1.8.7-p330 :004 > c % 1
=> 0.0

hahaha; the power of Ruby lies in the ease to fix itself :)