Mr. Li went to the Stationery Wholesale Department to buy prizes. He bought 3 boxes of pens at the wholesale price, 10 pens in each box, and the total cost was 144 yuan. How much cheaper is each pen than the retail price? (Pen retail price: 5.4 yuan/stick)
李老师到文化用品批发部买奖品，按批发价买了3盒钢笔，每盒10枝，一共用了144元，这样每枝钢笔比零售价便宜多少元？(钢笔零售价：5.4元/枝)
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">144 / 30</gadget>
<output>24/5 = around 4.8</output>

<gadget id="calculator">5.4 - (24/5)</gadget>
<output>0.6</output>

<result>0.6</result>