The store bought 150 Chinese knots, and there are 12 remaining after 2 days of selling. How many knots are sold on average per day?
商店进了150个中国结，卖了2天还剩12个，平均每天大约卖多少个？
<gadget id="calculator">150 - 12</gadget>
<output>138</output>

<gadget id="calculator">138 / 2</gadget>
<output>69</output>

<result>69</result>