Xiaozhang reads a storybook. He reads (1/4) of this storybook on the first day, (2/5) of this storybook on the second day, and reads the rest on the third day. How much did you watch in three days? What did you watch the most that day?
小张看一本故事书，第一天看了这本故事书的(1/4)，第二天看了这本故事书的(2/5)，剩下的第三天看完，第三天看了几分之几？那天看的最多？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<result>7/20 = around 0.35</result>