After reading a storybook, Xiao Ming read 20 pages a day for the first 5 days, and 30 pages a day for the next 2 days. How many pages does this book have?
小明看完一本故事书，前5天每天看20页，后2天每天30页．这本书共有多少页？
<gadget id="calculator">5 * 20</gadget>
<output>100</output>

<gadget id="calculator">2 * 30</gadget>
<output>60</output>

<gadget id="calculator">100 + 60</gadget>
<output>160</output>

<result>160</result>