Read a 90-page extra-curricular book, read it on the first day (5/15), and read it from the first page the next day.
看一本90页的课外书，第一天看了(5/15)，第二天从第多少页看起．
<gadget id="calculator">5 / 15</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">90 * (1/3)</gadget>
<output>30</output>

<gadget id="calculator">30 + 1</gadget>
<output>31</output>

<result>31</result>