A book has 120 pages, read the whole book (2/5) on the first day, and start from the page number on the second day.
一本书120页，第一天看了全书的(2/5)，第二天从第多少页看起．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">120 * (2/5)</gadget>
<output>48</output>

<gadget id="calculator">48 + 1</gadget>
<output>49</output>

<result>49</result>