The actual cost of a bridge is 21 million yuan, which is 5% more than the original plan. How much is the original plan?
一座桥实际造价2100万元，比原计划多用了5%，原计划造价多少万元？
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 + (1/20)</gadget>
<output>21/20 = around 1.05</output>

<gadget id="calculator">2_100 / (21/20)</gadget>
<output>2_000</output>

<result>2_000</result>