Produce a batch of parts, 35% of this batch of parts has been produced, and after 100 more parts are produced, the ratio of unproduced parts to produced parts is 2:3. How many parts are there in this batch?
生产一批零件，已经生产了这批零件的35%，再生产100个后，未生产的与已生产的比是2：3．这批零件有多少个？
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">(3/5) - (7/20)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">100 / (1/4)</gadget>
<output>400</output>

<result>400</result>