What is the area of a square whose side length is 3 decimeters?
一个边长是3分米的正方形，面积是多少平方厘米．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">9 * 100</gadget>
<output>900</output>

<result>900</result>