There are 20 steps on the first floor, and Xiao Ming lives on the 5th floor, so how many steps does he have to climb when he comes home from school?
一层楼的台阶为20级，小明家住在5楼，那么他放学回家共要爬多少级台阶．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

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

<result>80</result>