A workshop processes a batch of parts, the ratio of the number of processed parts to the total number is 2:5, and 300 more parts are processed to complete (3/5) of this batch of parts. How many parts are there in total?
一车间加工一批零件，已加工的个数与总个数的比是2：5，再加工300个，就完成这批零件的(3/5)了．这批零件一共多少个？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">300 / (1/5)</gadget>
<output>1_500</output>

<result>1_500</result>