Xiao Ming reads a story book, read this book on the first day (5/13), read this book on the second day (2/13), read this book less on the third day than the previous two days (4/13), how much of this book did you read on the third day?
小明看一本故事书，第一天看了这本书的(5/13)，第二天看了这本书的(2/13)，第三天比前两天少看这本书的(4/13)，第三天看了这本书的几分之几？
<gadget id="calculator">5 / 13</gadget>
<output>5/13 = around 0.384615</output>

<gadget id="calculator">2 / 13</gadget>
<output>2/13 = around 0.153846</output>

<gadget id="calculator">4 / 13</gadget>
<output>4/13 = around 0.307692</output>

<gadget id="calculator">(2/13) - (4/13)</gadget>
<output>-2/13 = around -0.153846</output>

<gadget id="calculator">(5/13) + (-2/13)</gadget>
<output>3/13 = around 0.230769</output>

<result>3/13 = around 0.230769</result>