A factory planned to produce a batch of parts in May, and completed the plan in the first half of the month (7/10). In the second half of the month, 50 more parts were completed than in the first half of the month. As a result, 450 more parts were actually produced than planned. How many parts were planned to be produced in May? ?
某工厂五月份计划生产一批零件，上半月完成了计划的(7/10)，下半月比上半月多完成了50个，结果实际比计划多生产了450个，五月份计划生产零件多少个？
<gadget id="calculator">450 - 50</gadget>
<output>400</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(7/10) * 2</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">(7/5) - 1</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">400 / (2/5)</gadget>
<output>1_000</output>

<result>1_000</result>