Money#format is the most complicated thing ever.

nih_money.rb

module NihMoney                                                                  
  def nih_money_units money                                                      
    if money.cents % money.currency.subunit_to_unit == 0                         
      money.cents / money.currency.subunit_to_unit                               
    else                                                                         
      money.cents.to_f / money.currency.subunit_to_unit                          
    end                                                                          
  end                                                                            
                                                                                 
  def nih_humanized_money_with_symbol money                                      
    "#{money.currency.symbol}#{nih_money_units(money)}"                          
  end                                                                            
end