What is the volume of a cone with a base area of 9 square meters and a height of 30 decimeters?
一个圆锥的底面积是9平方米，高30分米，它的体积是多少．
<gadget id="calculator">30 / 10</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) * 9 * 3</gadget>
<output>9</output>

<result>9</result>