factory produces a batch of parts, the first half of the month completes the plan (3/8), and the second half of the month completes the plan (2/5), what percentage of this batch of parts is still unfinished?
某工厂生产一批零件，上半月完成计划的(3/8)，下半月完成计划的(2/5)，这批零件还剩几分之几没有完成？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (3/8) - (2/5)</gadget>
<output>9/40 = around 0.225</output>

<result>9/40 = around 0.225</result>