Xiaoying reads a storybook with 188 pages. In the first 4 days, she reads an average of 17 pages a day, and after that, she reads 20 pages a day. How long will it take to finish it? (Please check the obtained number as a known number after you answer it).
小英看一本故事书有188页，前4天平均每天看17页，以后每天看20页，还要几天可以看完？(请你解答后，把得数当作已知数来检验一下)．
<gadget id="calculator">4 * 17</gadget>
<output>68</output>

<gadget id="calculator">188 - 68</gadget>
<output>120</output>

<gadget id="calculator">120 / 20</gadget>
<output>6</output>

<result>6</result>