The school assigns the task of maintaining 72 small trees on campus to Classes 1 and 2 according to the ratio of 5:4. What is the task of class 1 to maintain the small trees?
学校把养护校园内72棵小树的任务按5：4分配给六1、六2两个班，分给六1班养护小树的任务是多少棵．
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">72 * (5/9)</gadget>
<output>40</output>

<result>40</result>