The ink factory has produced 45,000 bottles of ink, 40% of which are red ink, and the rest are black ink. How many bottles of black ink are there more than red ink?
墨水厂生产了45000瓶墨水，其中40%是红墨水，其余的是黑墨水，黑墨水比红墨水多多少瓶？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">45_000 * (2/5)</gadget>
<output>18_000</output>

<gadget id="calculator">45_000 - 18_000 - 18_000</gadget>
<output>9_000</output>

<result>9_000</result>