To make a drawer with a length of 50 cm, a width of 40 cm, and a depth of 6 cm, at least how many square centimeters of wooden boards are needed.
做一个长50厘米，宽40厘米，深6厘米的抽屉，至少需要木板多少平方厘米．
<gadget id="calculator">50 * 40</gadget>
<output>2_000</output>

<gadget id="calculator">50 * 6</gadget>
<output>300</output>

<gadget id="calculator">40 * 6</gadget>
<output>240</output>

<gadget id="calculator">300 + 240</gadget>
<output>540</output>

<gadget id="calculator">540 * 2</gadget>
<output>1_080</output>

<gadget id="calculator">2_000 + 1_080</gadget>
<output>3_080</output>

<result>3_080</result>