Xiaojun reads a story book and has read 84 pages. The number of remaining pages is twice that of what has been read. If you want to finish reading the remaining pages within 8 days, how many pages do you read on average per day?
小军读一本故事书，已经读了84页．剩下的页数是已经读了的两倍，如果要把剩下的页数在8天内读完，平均每天读多少页？
<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">84 * (1/4)</gadget>
<output>21</output>

<result>21</result>