There is a batch of steel pipes piled up in a trapezoidal shape, with 6 on the top and 13 on the lower layer, a total of 8 layers. How many steel pipes are there in total?
有一批钢管堆放成梯形，顶成放6根，下层放13根，一共放了8层．这批钢管共有多少根？
<gadget id="calculator">6 + 13</gadget>
<output>19</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">19 * 4</gadget>
<output>76</output>

<result>76</result>