Xiao Ming needs 12 days to read a storybook, 18 pages per day for the first 5 days, and 20 pages per day for the next 7 days. How many pages does this book have?
一本故事书小明要12天看完，前5天每天看18页，后7天每天20页．这本书共有多少页？
<gadget id="calculator">5 * 18</gadget>
<output>90</output>

<gadget id="calculator">7 * 20</gadget>
<output>140</output>

<gadget id="calculator">90 + 140</gadget>
<output>230</output>

<result>230</result>