A vegetable field with a length of 300 meters and a width of 200 meters has a square pond with a length of 100 meters in the center of the vegetable field. This vegetable field can earn 20,000 yuan per hectare per year. How much can this vegetable field earn in a year? ?
一块长300米，宽200米的菜地，菜地中央有一边长100米的正方形水塘，这块菜地每公顷一年可以收人20000元，这块菜地一年可以收入多少万元？
<gadget id="calculator">300 * 200</gadget>
<output>60_000</output>

<gadget id="calculator">100 * 100</gadget>
<output>10_000</output>

<gadget id="calculator">60_000 - 10_000</gadget>
<output>50_000</output>

<gadget id="calculator">50_000 / 10_000</gadget>
<output>5</output>

<gadget id="calculator">20_000 / 10_000</gadget>
<output>2</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<result>10</result>