Master Zhang processes a batch of parts, and has processed (1/4) of these parts. If 50 more are processed, just half of this batch of parts will be completed. How many parts are there in this batch?
张师傅加工一批零件，已加工了这批零件的(1/4)．如果再加工50个，正好完成这批零件的一半．这批零件共有多少个？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">50 / (1/4)</gadget>
<output>200</output>

<result>200</result>