Tongji Primary School organized a tree planting activity in spring. It is known that 180 trees have been planted. If another 120 trees are planted, the number of trees already planted will be doubled. How many trees will be planted in total?
同济小学组织春季植树活动，已知植了180棵，如果再植120棵，已经植树的棵数就是剩下的二倍，问总共要植树多少棵？
<gadget id="calculator">180 + 120</gadget>
<output>300</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">300 / (2/3)</gadget>
<output>450</output>

<result>450</result>