If a rectangle is 5cm long and 4cm wide, what is the area of the rectangle when it is enlarged 2:1?
一个长方形长5cm，宽4cm，按2：1扩大后的长方形的面积是多少平方厘米．
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">10 * 8</gadget>
<output>80</output>

<result>80</result>