Xiaohong reads a story book. She reads (1/7) of this book on the first day, and (1/5) of this book on the second day. What percentage of the story is left?
小红看一本故事书，第一天看了这本书的(1/7)，第二天看了这本书的(1/5)，还剩几分之几没看？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/7) + (1/5)</gadget>
<output>12/35 = around 0.342857</output>

<gadget id="calculator">1 - (12/35)</gadget>
<output>23/35 = around 0.657143</output>

<result>23/35 = around 0.657143</result>