Experimental Primary School donated money to support the disaster area. The fourth, fifth and sixth grades donated a total of 54,000 yuan. The ratio of their donations was 5:6:7. How much did the sixth grade donate?
实验小学为支援灾区捐款，四、五、六年级共捐款54000元，他们捐款钱数的比是5：6：7，六年级捐款多少元？
<gadget id="calculator">5 + 6 + 7</gadget>
<output>18</output>

<gadget id="calculator">54_000 / 18</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 * 7</gadget>
<output>21_000</output>

<result>21_000</result>