class RuboCop::Cop::Style::ExponentialNotation

def engineering?(node)
  mantissa, exponent = node.source.split('e')
  return false unless /^-?\d+$/.match?(exponent)
  return false unless (exponent.to_i % 3).zero?
  return false if /^-?\d{4}/.match?(mantissa)
  return false if /^-?0\d/.match?(mantissa)
  return false if /^-?0.0/.match?(mantissa)
  true
end