There are a pile of steel pipes of uniform thickness. There are 5 steel pipes on the top layer and 26 steel pipes on the bottom layer. There are 124 steel pipes in total.
有一堆粗细均匀的钢管，最上面一层有5根，最下面一层有26根，共124根，相邻两层相差的根数相等，那么，相邻两层相差多少根钢管？
<gadget id="calculator">26 - 5</gadget>
<output>21</output>

<gadget id="calculator">26 + 5</gadget>
<output>31</output>

<gadget id="calculator">2 / 31</gadget>
<output>2/31 = around 0.064516</output>

<gadget id="calculator">124 * (2/31)</gadget>
<output>8</output>

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">21 / 7</gadget>
<output>3</output>

<result>3</result>