Yangshan Elementary School participated in the tree planting activity, with an average of 80 trees for each grade, among which the ratio of trees for grades 4, 5, and 6 was 2:3:5. How many more trees were planted in sixth grade than in fourth grade?
阳山小学参加植树活动，平均每个年级分得80棵，其中四、五、六三个年级棵树的比是2：3：5．六年级比四年级多植了多少棵？
<gadget id="calculator">2 + 3 + 5</gadget>
<output>10</output>

<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">80 * 3 * (1/2)</gadget>
<output>120</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">80 * 3 * (1/5)</gadget>
<output>48</output>

<gadget id="calculator">120 - 48</gadget>
<output>72</output>

<result>72</result>