The school assigns 540 tree planting tasks to the fourth, fifth and sixth grades according to the ratio of 5:6:7. How many trees should be planted in the sixth grade?
学校把540棵植树任务按5：6：7分给四、五、六年级完成，六年级应植树多少棵？
<gadget id="calculator">5 + 6 + 7</gadget>
<output>18</output>

<gadget id="calculator">7 / 18</gadget>
<output>7/18 = around 0.388889</output>

<gadget id="calculator">540 * (7/18)</gadget>
<output>210</output>

<result>210</result>