The building where Xiaohong lives has seven floors, and each floor has 20 stairs. Her family lives on the fifth floor. Do you know how many stairs Xiaohong takes to get to the floor where she lives.
小红住的这幢楼共七层，每层楼梯20级，她家住在5楼，你知道小红走多少级楼梯才能到自己住的那一层．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>