Xiao Ming reads a book. He reads (2/5) of the whole book on the first day, and (1/3) of the first day on the second day. What percentage of the book is left unread?
小明看一本书，第一天看了全书的(2/5)，第二天看的是第一天的(1/3)，还剩这本书的几分之几没有看？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) * (1/3)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">1 - (2/5) - (2/15)</gadget>
<output>7/15 = around 0.466667</output>

<result>7/15 = around 0.466667</result>