Make 6 display boxes with wooden boards, and use wooden boards on all sides except glass on the front. It is known that the display box is 2 meters long, 0.5 meters wide, and 1.5 meters high. How many square meters of wooden boards are needed?
用木板做6个陈列箱，除它的正面用玻璃外，其余各面都用木板．已知陈列箱长2米，宽0.5米，高1.5米，共需要木板多少平方米？
<gadget id="calculator">2 * 0.5</gadget>
<output>1</output>

<gadget id="calculator">0.5 * 1.5</gadget>
<output>0.75</output>

<gadget id="calculator">1 + 0.75</gadget>
<output>1.75</output>

<gadget id="calculator">1.75 * 2</gadget>
<output>3.5</output>

<gadget id="calculator">2 * 1.5</gadget>
<output>3</output>

<gadget id="calculator">3.5 + 3</gadget>
<output>6.5</output>

<gadget id="calculator">6.5 * 6</gadget>
<output>39</output>

<result>39</result>