In response to the low-carbon lifestyle of green travel, Dad decided to buy 3 bicycles for his family, each at 138 yuan. How much is the total cost?
为了响应绿色出行的低碳生活方式，爸爸决定给家人买3辆自行车，每辆自行车138元，问一共需要多少元？
<gadget id="calculator">138 * 3</gadget>
<output>414</output>

<result>414</result>