The story book has 126 pages. Wang Li reads 7 pages every day for 9 days. How many pages are left?
故事书有126页，王丽每天看7页，看了9天，还剩多少页．
<gadget id="calculator">7 * 9</gadget>
<output>63</output>

<gadget id="calculator">126 - 63</gadget>
<output>63</output>

<result>63</result>