Xingnong Chemical Fertilizer Factory completed the full-month production plan in the first half of May (4/9), and produced 250 tons less fertilizer than the second half. As a result, the full-month fertilizer production exceeded the plan by 450 tons. How many tons of fertilizer is planned to be produced in the whole month?
兴农化肥厂五月份上半月完成了全月生产计划的(4/9)，比下半月少生产化肥250吨，结果全月生产的化肥超过计划450吨．全月计划生产化肥多少吨？
<gadget id="calculator">450 - 250</gadget>
<output>200</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(4/9) * 2</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">1 - (8/9)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">200 / (1/9)</gadget>
<output>1_800</output>

<result>1_800</result>