A rectangular forest farm is 4,000 meters wide. It takes two hours for a ranger to cycle around the forest farm at a speed of 12 kilometers per hour. What is the area of the forest farm in hectares?
一个长方形的林场，宽是4000米，护林员骑自行车以每小时12千米的速度绕林场巡视一周要2小时，问这个林场的面积是多少公顷？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">12 * 1_000 * 1</gadget>
<output>12_000</output>

<gadget id="calculator">12_000 - 4_000</gadget>
<output>8_000</output>

<gadget id="calculator">4_000 / 10_000</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">8_000 * (2/5)</gadget>
<output>3_200</output>

<result>3_200</result>