A book has 36 pages. Xiao Ming reads (2/9) on the first day and (1/3) on the second day. What page should he read on the third day?
一本书有36页，小明第一天看了(2/9)第二天看了(1/3)，第三天应从第几页看起？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/9) + (1/3)</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">36 * (5/9)</gadget>
<output>20</output>

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

<result>21</result>