There are the same number of stairs on each floor of a building. Xiao Ming walks from the ground floor to three floors and walks 42 stairs. According to this calculation, how many stairs do you need to walk from the ground floor to the six floors?
一幢大楼每层楼的楼梯阶数同样多，小明从底层走上三层楼，跨了42阶楼梯．照这样计算，要从底层走上六层楼，需要跨多少阶楼梯？
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">21 * 5</gadget>
<output>105</output>

<result>105</result>