The side length of a square is 40 cm, what is its area?
一个正方形的边长是40厘米，它的面积是多少平方分米？
<gadget id="calculator">40 / 10</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>