Little Ding Ding reads a storybook, plans to read 21 pages a day, reads it in 8 days, and actually finishes it in a week. How many pages do you actually read per day?
小丁丁看一本故事书，计划每天看21页，8天看完，实际一周就看完了．实际每天多看多少页？
<gadget id="calculator">8 / 7</gadget>
<output>8/7 = around 1.142857</output>

<gadget id="calculator">21 * (8/7)</gadget>
<output>24</output>

<gadget id="calculator">24 - 21</gadget>
<output>3</output>

<result>3</result>