Xiao Ming and Xiao Hua are reading the same book, when Xiao Ming has read (1/3), Xiao Hua has 90 pages left to read. When Xiao Ming continued to read the remaining half, Xiao Hua just read half of the book. How many pages does this book have?
小明和小华读同一本书，当小明读了(1/3)，小华还剩90页没读．当小明继续读完所剩下的一半时候，小华正好读了全书一半，这本书一共多少页？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(2/3) - (1/6)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">60 / (1/2)</gadget>
<output>120</output>

<result>120</result>