docs: def start(st_reg_number):
          """Checks the number valiaty for the Amazonas state"""
          weights = range(2, 10)
          digits = st_reg_number[0:len(st_reg_number) - 1]
          control_digit = 11
          check_digit = st_reg_number[-1:]
  
          if len(st_reg_number) != 9:
                  return False
  
          sum_total = 0
  
          for i in weights:
                  sum_total = sum_total + i * int(digits[i-2])
  
          if sum_total < control_digit:
                  control_digit = 11 - sum_total
                  return str(digit_calculated) == check_digit
  
          elif sum_total % 11 <= 1:
                  return '0' == check_digit
  
          else:
                  digit_calculated = 11 - sum_total % 11
                  return str(digit_calculated) == check_digit