A batch of logs is stacked on the ground, there is a difference between each layer, 6 logs on the top layer, and 14 logs on the bottom layer, how many logs are there in total in this pile?
一批圆木堆放在地上，每层之间相差一根，最上层6根，最下层14根，这堆圆木共多少根．
<gadget id="calculator">6 + 14</gadget>
<output>20</output>

<gadget id="calculator">14 - 6</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">20 * (9/2)</gadget>
<output>90</output>

<result>90</result>