There is a batch of rice in the grain station, sell (2/9) on the first day, sell the rest (1/7) on the second day, and make up the rest (1/2) on the third day. At this time, there were still 1,890 kilograms of rice in the grain station. How many kilograms of rice did the grain station have?
粮站有一批大米，第一天卖出(2/9)，第二天卖出剩下的(1/7)，第三天补进第二天剩下的(1/2)．这时粮站还存有大米1890千克，问粮站原来有大米多少千克？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 - (2/9)</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(7/9) * (1/7)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 - (2/9) - (1/9)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(2/3) * (3/2)</gadget>
<output>1</output>

<gadget id="calculator">1_890 / 1</gadget>
<output>1_890</output>

<result>1_890</result>