It took Xiaoxin 3 weeks to finish reading a 315-page storybook. How many pages of story books does he read on average every day?
小新用了3个星期刚好把一本315页的故事书看完．他平均每天看几页故事书？
<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">315 / 21</gadget>
<output>15</output>

<result>15</result>