Lan Lan reads a story book, and has already read 45 pages, and there are 55 pages left. What fraction of the total number of pages does Lan Lan read?
兰兰看一本故事书，已经看了45页，还有55页没有看，兰兰看的页数是这本书总页数的几分之几？
<gadget id="calculator">45 + 55</gadget>
<output>100</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<result>9/20 = around 0.45</result>