There is a pile of logs, with 6 logs on the top floor and 10 logs on the bottom floor. The difference between two adjacent floors is 1 log. How many logs are there in this pile?
有一堆圆木，最上层6根，最下层10根，每相邻的两层都相差1根，这堆圆木共有多少根．
<gadget id="calculator">10 + 6</gadget>
<output>16</output>

<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">16 * (5/2)</gadget>
<output>40</output>

<result>40</result>