Xiaoqiang read a 360-page literature book, and read 20% of it in the first 4 days. At this speed, how many days will it take for Xiaoqiang to finish reading this book?
小强看一本360页的文学书，前4天看了20%．照这样速度，小强看完这本书一共要多少天？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">4 / (1/5)</gadget>
<output>20</output>

<result>20</result>