In a pile of steel pipes, there are 3 steel pipes in the uppermost layer and 13 steel pipes in the lowermost layer. The difference between each two adjacent layers is 1 steel pipe. How many steel pipes are there in total in this pile?
一堆钢管，最上层有3根，最下层有13根，每相邻两层相差1根，这堆钢管一共有多少根．
<gadget id="calculator">3 + 13</gadget>
<output>16</output>

<gadget id="calculator">13 - 3</gadget>
<output>10</output>

<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">11 / 2</gadget>
<output>11/2 = around 5.5</output>

<gadget id="calculator">16 * (11/2)</gadget>
<output>88</output>

<result>88</result>