A pile of steel pipes has 10 steel pipes in the bottom layer. There are 6 layers in total. The difference between two adjacent layers is 1. How many steel pipes are there in total?
一堆钢管，最下层有10根，共有6层，相邻两层差1根，共有多少根．
<gadget id="calculator">1 - 6</gadget>
<output>-5</output>

<gadget id="calculator">10 + (-5)</gadget>
<output>5</output>

<gadget id="calculator">5 + 10</gadget>
<output>15</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>