A book has 300 pages, and I plan to read 35 pages a day, and after 8 days, how many pages are left?
一本书有300页，计划每天看35页，看了8天，还剩多少页没有看？
<gadget id="calculator">35 * 8</gadget>
<output>280</output>

<gadget id="calculator">300 - 280</gadget>
<output>20</output>

<result>20</result>