A factory processes parts with iron billets on a lathe. One iron billet can only process one part, and it is known that every 9 iron billets can be cast into another iron billet from the iron filings. Now there are 729 iron billets, how many parts can be processed according to the above method?
某工厂在车床上用铁坯加工零件．一个铁坯只能加工一个零件，已知每9个铁坯车下的铁屑又可以铸成一个铁坯．现在有729个铁坯，按照以上的方法可以加工多少个零件？
<gadget id="calculator">729 / 9</gadget>
<output>81</output>

<gadget id="calculator">729 / 9 / 9</gadget>
<output>9</output>

<gadget id="calculator">9 / 9</gadget>
<output>1</output>

<gadget id="calculator">729 + 81 + 9 + 1</gadget>
<output>820</output>

<result>820</result>