Roman numerals

def new_roman_num num
roman_num = '' 
    digit = num/1000
    if digit > 0
      roman_num += ('M' * digit)
      num = num - (1000 * digit)
    end
    digit = num/100
    if digit == 4
      roman_num += 'CD'
      num -= 400
      digit -= 4
    elsif digit == 9 
      roman_num += 'CM'
      num -= 900
      digit -= 900
    end
    if digit >= 5 
      roman_num += 'D'
      num = num - 500
      digit -= 5
    end
    if digit > 0 
      roman_num += ('C' * digit)
      num = num - 100*digit
    end
    digit = num/10
    if digit == 4
      roman_num += 'XL'
      num -= 40
      digit -= 4
    elsif digit == 9
      roman_num += 'XC'
      num -= 90
      digit -= 9
    end
    if digit >= 5
      roman_num += 'L'
      num -= 50
      digit -= 5
    end
    if digit > 0   
      roman_num +=('X' * digit)
      num -= 10 * digit
    end
    if num == 4
      roman_num += 'IV'
      num -= 4
    elsif num == 9
      roman_num += 'IX'
      num -= 9
    end
    if num >= 5
      roman_num += 'V'
      num -= 5
    end
    if num > 0   
      roman_num += ('I' * num)
    end
  return roman_num
 end 
             
      
puts 'enter an integer between 1 and 3,000:'
num1 = gets.chomp.to_i

print new_roman_num num1
print "\n"