The school will paint the walls and ceiling of each classroom. Each classroom is measured to be 8 meters long, 7 meters wide, and 3 meters high, of which the doors, windows and blackboards occupy about 30 square meters. How many square meters is the area to be painted in each classroom?
学校将粉刷每间教室的四壁和顶面．每间教室经测量，长8米、宽7米、高3米，其中门窗和黑板大约占30平方米，每间教室要粉刷的面积是多少平方米？
<gadget id="calculator">8 * 7</gadget>
<output>56</output>

<gadget id="calculator">8 * 3 * 2</gadget>
<output>48</output>

<gadget id="calculator">7 * 3 * 2</gadget>
<output>42</output>

<gadget id="calculator">42 - 30</gadget>
<output>12</output>

<gadget id="calculator">56 + 48 + 12</gadget>
<output>116</output>

<result>116</result>