If you read a 200-page storybook, you have read it for 15 days, and you haven’t read the remaining 20 pages. How many pages do you read every day on average?
读一本200页的故事书，已经读了15天，剩下20页没看，平均每天读多少页？
<gadget id="calculator">200 - 20</gadget>
<output>180</output>

<gadget id="calculator">180 / 15</gadget>
<output>12</output>

<result>12</result>