The third and fourth graders planted 40 trees in total, among which the third grade planted 16 trees, and the fourth grade was in charge of the rest. What percentage of the number of trees planted by the third grade was that of the fourth grade?
三、四年级同学共植树40棵，其中三年级植树16棵，剩下的由四年级负责，三年级植树的棵数是四年级的几分之几？
<gadget id="calculator">40 - 16</gadget>
<output>24</output>

<gadget id="calculator">16 / 24</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>