The knitting factory originally planned to produce 18,000 sets of sweatshirts in 20 days, but actually produced 100 sets more than planned every day. How many days earlier than planned could it actually be completed?
针织厂原计划20天生产运动衫18000套，实际每天比计划多生产100套，实际可比计划提前多少天完成？
<gadget id="calculator">18_000 / 20</gadget>
<output>900</output>

<gadget id="calculator">900 + 100</gadget>
<output>1_000</output>

<gadget id="calculator">18_000 / 1_000</gadget>
<output>18</output>

<gadget id="calculator">20 - 18</gadget>
<output>2</output>

<result>2</result>