An editor uses 10 numbers from 0 to 9 to mark each page of a book. If 636 numbers are written in total, how many pages does the book have?
某编辑用0～9这10个数字给一本书的各页标上页码，若共写了636个数字，则该书有多少页？
<gadget id="calculator">90 * 2</gadget>
<output>180</output>

<gadget id="calculator">636 - 9 - 180</gadget>
<output>447</output>

<gadget id="calculator">447 / 3</gadget>
<output>149</output>

<gadget id="calculator">99 + 149</gadget>
<output>248</output>

<result>248</result>