The fertilizer factory plans to produce 3,500 tons of fertilizers in the whole month. In fact, it completed the plan (3/5) in half a month, and produced the same amount in the second half of the month as the first half. How many tons more than planned in the whole month?
化肥厂计划全月生产化肥3500吨，实际上半月完成计划的(3/5)，下半月生产的和上半月同样多．全月比计划超产多少吨？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">3_500 * (3/5) * 2</gadget>
<output>4_200</output>

<gadget id="calculator">4_200 - 3_500</gadget>
<output>700</output>

<result>700</result>