On a plan with a scale of 1:4000, the length of the school playground is measured to be 3 cm and the width to be 2 cm. So what is the difference between the area on the map and the actual area of the playground?
在一幅比例尺为1：4000的平面图上，量得学校操场的长是3厘米，宽是2厘米．那么操场的图上面积与实际面积绋多少？
<gadget id="calculator">1 / 4_000</gadget>
<output>1/4_000 = around 0.00025</output>

<gadget id="calculator">2 / (1/4_000) / 100</gadget>
<output>80</output>

<gadget id="calculator">3 / (1/4_000) / 100</gadget>
<output>120</output>

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

<result>9_600</result>