There is an extra-curricular book, Xiao Ming has read 35 pages, which is exactly 20% of the book, how many pages are left unread?
有一本课外书，小明读了35页，正好是这本书的20%，还剩多少页没有读？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">35 / (1/5)</gadget>
<output>175</output>

<gadget id="calculator">175 - 35</gadget>
<output>140</output>

<result>140</result>