rope is 600 meters long, 120 meters are used for the first time, and 3 times as much as the first time is used for the second time, how many meters are left in the end? (Please briefly write down your own thinking process first, and then calculate the results in a column.)
一根绳子长600米，第一次用去了120米，第二次用去的是第一次用去的3倍，最后还剩多少米？(请你先把自己的思考过程简单写一写，然后再列式算出结果．)
<gadget id="calculator">120 * 3</gadget>
<output>360</output>

<gadget id="calculator">120 + 360</gadget>
<output>480</output>

<gadget id="calculator">600 - 480</gadget>
<output>120</output>

<result>120</result>