How many square centimeters of wooden boards are needed to make three cubic wooden boxes without a lid whose edge length is 30 centimeters?
做3个棱长是30厘米的无盖正方体木盒，需木板多少平方厘米？
<gadget id="calculator">30 * 30 * 5 * 3</gadget>
<output>13_500</output>

<result>13_500</result>