The transport team transports a batch of goods, 30 bags each time with a large truck, and can be transported 12 times. Now we use small trucks to transport the goods, and each time we transport 6 bags less than the large trucks, how many times does it take the small trucks to transport the goods?
运输队运一批货物，用大卡车每次运30袋，12次可以运完．现在改用小卡车来运，每次比大卡车少运6袋，小车需用多少次才能把这批货物运完？
<gadget id="calculator">30 - 6</gadget>
<output>24</output>

<gadget id="calculator">12 / 24</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">30 * (1/2)</gadget>
<output>15</output>

<result>15</result>