Xiaohong reads a book. On the first day, she reads (1/7) of the whole book. On the second day, she reads the remaining (1/3) and there are 3 more pages. How many pages are there?
小红看一本书，第一天看了全书的(1/7)，第二天看了剩下的(1/3)还多3页，这时还有137页没有看，这本书共多少页？
<gadget id="calculator">137 + 3</gadget>
<output>140</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

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

<gadget id="calculator">(6/7) * (1/3)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (1/7) - (2/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">140 / (4/7)</gadget>
<output>245</output>

<result>245</result>