The fruit shop shipped 150 kilograms of watermelon on the first day, and twice as much watermelon on the second day. How many kilograms were shipped in total in the two days?
水果店第一天运来西瓜150千克，第二天运来的是第一天的2倍，两天一共运来多少千克？
<gadget id="calculator">150 * 2</gadget>
<output>300</output>

<gadget id="calculator">300 + 150</gadget>
<output>450</output>

<result>450</result>