Xiaoming lives on the fourth floor. She has to walk 10 steps to go up each floor. How many steps does Xiaoming take to walk from the first floor to the fourth floor?
小聪明家住在四楼，她每上一层楼要走10级台阶，小聪明从一楼走到四楼要走多少级台阶．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<result>30</result>