If you read a book, you have read (1/3) more than 18 pages, and the remaining pages are 4 more than what you read. How many pages are in this book?
看一本书，已看(1/3)还多18页，余下的比看的多4页，这本书多少页？
<gadget id="calculator">18 + 18 + 4</gadget>
<output>40</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3) - (1/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">40 / (1/3)</gadget>
<output>120</output>

<result>120</result>