There were 2,560 tons of coal in the coal yard, and they were transported out once a day by 20 vehicles, with each vehicle carrying 8 tons of coal. After one week, how many tons of coal are left in the coal field?
煤场里原有2560吨煤，每天用20辆车往外运一次，每辆车载煤8吨．一个星期以后，煤场还剩多少吨煤？
<gadget id="calculator">8 * 20 * 7</gadget>
<output>1_120</output>

<gadget id="calculator">2_560 - 1_120</gadget>
<output>1_440</output>

<result>1_440</result>