To process a batch of parts, A first processes (2/5) of this batch of parts, and then B processes (1/2) of A. It is known that the number of parts processed by B is 200 less than that of A, how many parts are there in total?
加工一批零件，甲先加工了这批零件的(2/5)，接着乙加工了甲的(1/2)．已知乙加工的个数比甲少200个，这批零件共有多少个？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(2/5) * (1/2)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/5) - (1/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">200 / (1/5)</gadget>
<output>1_000</output>

<result>1_000</result>