In order to beautify the environment, the Municipal Corporation plans to plant 900 trees. The workers have been planting for 2 days, planting 150 trees every day, and the rest are going to be planted in 3 days. How many trees will be planted on average every day?
为了美化环境，市政公司计划种树900棵．工人们已经栽了2天，每天栽150棵，剩下的打算3天栽完，平均每天要栽多少棵？
<gadget id="calculator">150 * 2</gadget>
<output>300</output>

<gadget id="calculator">900 - 300</gadget>
<output>600</output>

<gadget id="calculator">600 / 3</gadget>
<output>200</output>

<result>200</result>