The total production value of Zhongxing Automobile Manufacturing Plant last year was 690 million yuan, which was 15% higher than the plan. How much is the total production value of the plant last year?
中兴汽车制造厂去年生产总值为6.9亿元，比计划超额了15%，该厂去年计划生产总值多少亿元？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 + (3/20)</gadget>
<output>23/20 = around 1.15</output>

<gadget id="calculator">6.9 / (23/20)</gadget>
<output>6</output>

<result>6</result>