The school organized sixth-grade students to plant trees. They completed 30% of the task on the first day, and 45% of the task on the second day. Just planted 300 trees in two days. How many trees will the sixth graders plant in total?
学校组织六年级同学植树，第一天完成了任务的30%，第二天又完成了任务的45%，两天正好植树300棵．六年级同学一共要植树多少棵？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">(3/10) + (9/20)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">300 / (3/4)</gadget>
<output>400</output>

<result>400</result>