Tiantian reads a story book, the ratio of the number of pages she has read to the number of pages she has not read is 5:7, she has read the whole book ((())/(())).
甜甜看一本故事书，已看页数与未看页数的比是5：7，她已看了全书的((())/(()))．
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<result>5/12 = around 0.416667</result>