There are a pile of trapezoidal ceramic tubes. There are 8 tubes in the upper layer and 16 tubes in the lower layer. There are 9 layers in total. How many ceramic tubes are there in this pile?
有一堆堆成梯形的陶瓷管，上层有8根，下层有16根，共9层，这堆陶瓷管有多少根．
<gadget id="calculator">8 + 16</gadget>
<output>24</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">24 * (9/2)</gadget>
<output>108</output>

<result>108</result>