A factory planned to produce a batch of parts in January. Due to the improvement of the production process, it produced (3/5) of the plan in the first half of the month, and produced (1/5) more in the second half of the month than the first half of the month. In this way, 1980 parts were actually produced in the whole month. Parts, how many parts are planned to be produced in January?
某工厂计划一月份生产一批零件，由于改进生产工艺，结果上半月生产了计划的(3/5)，下半月比上半月多生产了(1/5)，这样全月实际生产了1980个零件，则一月份计划生产多少个零件？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(3/5) * (6/5)</gadget>
<output>18/25 = around 0.72</output>

<gadget id="calculator">(3/5) + (18/25)</gadget>
<output>33/25 = around 1.32</output>

<gadget id="calculator">1_980 / (33/25)</gadget>
<output>1_500</output>

<result>1_500</result>