It takes 4 minutes for Xiaojun to walk from the first floor to the fifth floor. At this speed, how many minutes does it take him to walk from the first floor to the tenth floor?
小军从一楼走到五楼需要4分钟．按此速度，他从一楼走到十楼需要多少分钟．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">4 / 4</gadget>
<output>1</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">1 * 9</gadget>
<output>9</output>

<result>9</result>