Liu Xiao runs along the playground with a difference of 40 meters in length and width every morning. He runs 6 laps every day and runs a total of 2400 meters. He asks how many square meters the playground is.
刘晓每天早晨沿长和宽相差40米的操场跑步，每天跑6圈，共跑2400米，问这个操场的面积是多少平方米．
<gadget id="calculator">2_400 / 6</gadget>
<output>400</output>

<gadget id="calculator">400 / 2</gadget>
<output>200</output>

<gadget id="calculator">200 - 40</gadget>
<output>160</output>

<gadget id="calculator">160 / 2</gadget>
<output>80</output>

<gadget id="calculator">80 + 40</gadget>
<output>120</output>

<gadget id="calculator">80 * 120</gadget>
<output>9_600</output>

<result>9_600</result>