The original cost of a machine part is 4.5 yuan. After improving the technology, it is reduced by 15%. How much is the current cost per piece?
一种机器零件原来成本4.5元，改进技术后，降低了15%，现在的成本是每件多少元？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">4.5 * (17/20)</gadget>
<output>3.825</output>

<result>3.825</result>