A book has 90 pages. Liangliang read it on the first day (2/9), how many pages should he read on the second day.
一本书90页，亮亮第一天看了(2/9)，第二天应从第多少页看起．
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">90 * (2/9)</gadget>
<output>20</output>

<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<result>21</result>