Wang Xiaoqian read a storybook in 4 days, an average of 45 pages per day in the first 2 days, and a total of 85 pages in the last 2 days. Do you know how many pages this book has?
王小倩同学4天看完一本故事书，前2天平均每天看45页，后2天共看了85页．你知道这本书一共有多少页吗？
<gadget id="calculator">45 * 2</gadget>
<output>90</output>

<gadget id="calculator">90 + 85</gadget>
<output>175</output>

<result>175</result>