Daqingshan Forest Farm plans to plant 800 trees this year. It has been planted for 3 days, and 140 trees are loaded every day, and the rest will be planted in 2 days. How many trees are planted per day on average?
大青山林场今年计划植树800棵．已经栽了3天，每天载了140棵，剩下的打算用2天时间栽完．平均每天要栽多少棵？
<gadget id="calculator">140 * 3</gadget>
<output>420</output>

<gadget id="calculator">800 - 420</gadget>
<output>380</output>

<gadget id="calculator">380 / 2</gadget>
<output>190</output>

<result>190</result>