To process 1116 parts, Master Zhang processes 78 parts per hour, and Master Li processes 6 parts less than Master Zhang per hour. Now Master Li will process it for 2.5 hours first, and then Master Zhang will do it. How many hours will Master Zhang do?
要加工1116个零件，张师傅每小时加工78个，李师傅每小时比张师傅少加工6个．现在由李师傅先加工2.5小时，再由张师傅做，张师傅还要做几小时？
<gadget id="calculator">78 - 6</gadget>
<output>72</output>

<gadget id="calculator">72 * 2.5</gadget>
<output>180</output>

<gadget id="calculator">1_116 - 180</gadget>
<output>936</output>

<gadget id="calculator">936 / 78</gadget>
<output>12</output>

<result>12</result>