The cafeteria bought 280 kilograms of flour and three times as much rice as flour. How many kilograms of grain did they buy in total?
食堂买来面粉280千克，买来的大米是面粉的3倍，一共买来多少千克粮食？
<gadget id="calculator">280 * 3</gadget>
<output>840</output>

<gadget id="calculator">840 + 280</gadget>
<output>1_120</output>

<result>1_120</result>