100-page homework is obviously finished in the first week (2/5) and finished in the second week (1/4). How many pages are completed in two weeks?
一本100页的作业，明明第一周做完(2/5)，第二周做完了(1/4)，两周共做完多少页？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/5) + (1/4)</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">100 * (13/20)</gadget>
<output>65</output>

<result>65</result>