The desk is 60 centimeters long, and the measured length around it is 200 centimeters. What is the area of the desk?
课桌长60厘米，经测量四周长度是200厘米，那桌面的面积有多大？
<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<gadget id="calculator">100 - 60</gadget>
<output>40</output>

<gadget id="calculator">60 * 40</gadget>
<output>2_400</output>

<result>2_400</result>