Huanhuan has been reading a 240-page children's novel for 6 days, 30 pages a day, how many pages are left?
欢欢看一本240页的儿童小说，已经看了6天，每天看30页，还剩下多少页没有看？
<gadget id="calculator">6 * 30</gadget>
<output>180</output>

<gadget id="calculator">240 - 180</gadget>
<output>60</output>

<result>60</result>