Xiao Ming reads a book and reads 90 pages every week, and there is still (1/3) of this book left. How many pages does this book have?
小明看一本书，每一周看了90页，还剩下这本书的(1/3)，这本书有多少页？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">90 / (2/3)</gadget>
<output>135</output>

<result>135</result>