There are a pile of steel pipes, there are 10 steel pipes in the uppermost layer, and 18 steel pipes in the lowermost layer. (The difference between two adjacent layers is 1 steel pipe.) How many steel pipes are there in this pile?
有一堆钢管，最上层有10根，最下层有18根，(每相邻的两层相差1根)这堆钢管一共有多少根？
<gadget id="calculator">10 + 18</gadget>
<output>28</output>

<gadget id="calculator">18 - 10</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

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

<gadget id="calculator">28 * (9/2)</gadget>
<output>126</output>

<result>126</result>