If the length of a rectangle is 8 decimeters and the width is 5 centimeters, what is its area in square centimetres?
一个长方形的长是8分米，宽是5厘米，它的面积是多少平方厘米
<gadget id="calculator">8 * 10</gadget>
<output>80</output>

<gadget id="calculator">80 * 5</gadget>
<output>400</output>

<result>400</result>