The bookstore shipped 1050 books, sold (2/7) of the total in the morning, and (1/5) of the total sold in the afternoon, how many books are left?
书店运来图书1050册，上午卖出总数的(2/7)，下午卖出总数的(1/5)，还剩多少册？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (2/7) - (1/5)</gadget>
<output>18/35 = around 0.514286</output>

<gadget id="calculator">1_050 * (18/35)</gadget>
<output>540</output>

<result>540</result>