Xiao Gao reads a book and reads the whole book on the first day (11/15), what percentage of the book is left unread?
小高读一本书，第一天读了全书的(11/15)，还剩这本书的几分之几没读？
<gadget id="calculator">11 / 15</gadget>
<output>11/15 = around 0.733333</output>

<gadget id="calculator">1 - (11/15)</gadget>
<output>4/15 = around 0.266667</output>

<result>4/15 = around 0.266667</result>