car transports 100 pieces of porcelain to a porcelain factory. If one piece is delivered, the shipping fee is 2 yuan. If one piece is damaged, the shipping fee will not be paid, but the factory will be compensated for 8 yuan. As a result, the shipping cost was only 170 yuan. How many pieces did he damage?
一辆汽车给瓷器厂运瓷器100件，运到1件给运费2元，损坏1件不但不给运费，反而赔偿厂方8元．结果只得运费170元，他损坏了几件？
<gadget id="calculator">100 * 2</gadget>
<output>200</output>

<gadget id="calculator">200 - 170</gadget>
<output>30</output>

<gadget id="calculator">2 + 8</gadget>
<output>10</output>

<gadget id="calculator">30 / 10</gadget>
<output>3</output>

<result>3</result>