Xiaohong reads a story book, the ratio of the number of pages she has read to the number of pages she has not read is 2:7, she has read 24 pages, how many pages are left?
小红读一本故事书，已读的和未读的页数的比是2﹕7，已经读了24页，还剩下多少页？
<gadget id="calculator">2 + 7</gadget>
<output>9</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">24 / (2/9)</gadget>
<output>108</output>

<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">108 * (7/9)</gadget>
<output>84</output>

<result>84</result>