There are 600 kilograms of eggs, 210 kilograms are sold in the first 6 days, and they are sold out in the remaining 3 days. How many kilograms are sold per day on average?
有600千克鸡蛋，前6天卖210千克，剩下的3天卖完，剩下的平均每天卖多少千克？
<gadget id="calculator">600 - 210</gadget>
<output>390</output>

<gadget id="calculator">390 / 3</gadget>
<output>130</output>

<result>130</result>