Each person can collect 6 kilograms of tree species per day. According to this calculation, there are 4 groups in Class 3 and Class 2, and each group has 9 people. How many kilograms of tree species can be collected in one day?
每人每天可以收集树种6千克，照这样计算，三2班有4个小组，每个小组9人，一天共收集树种多少千克？
<gadget id="calculator">4 * 9</gadget>
<output>36</output>

<gadget id="calculator">36 * 6</gadget>
<output>216</output>

<result>216</result>