A concrete brick is 5 decimeters long and wide and 9 centimeters thick. What is its volume?
一块水泥砖长和宽都是5分米，厚是9厘米．它的体积是多少？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">5 * 5 * (9/10)</gadget>
<output>45/2 = around 22.5</output>

<result>45/2 = around 22.5</result>