The paper mill completed 75% of the annual plan in the first seven months of last year, and produced 1,600 tons in the last five months, which just completed the task. If it is to exceed 10% of the annual plan, how many tons will it need to produce?
造纸厂去年前七个月完成全年计划的75%，后五个月又生产了1600吨，正好完成任务，若要超产全年计划的10%，还需生产多少吨？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

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

<gadget id="calculator">1_600 / (1/4)</gadget>
<output>6_400</output>

<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">6_400 * (1/10)</gadget>
<output>640</output>

<result>640</result>