A book with 500 pages, read 15% on the first day and 10% on the second day, what page should be read from the third day.
一本书500页，第一天读了15%，第二天读了10%，第三天应该从第多少页读起．
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">500 * (3/20)</gadget>
<output>75</output>

<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">500 * (1/10)</gadget>
<output>50</output>

<gadget id="calculator">75 + 50</gadget>
<output>125</output>

<gadget id="calculator">125 + 1</gadget>
<output>126</output>

<result>126</result>