Shengli Road Primary School launched a donation activity for the Indian Ocean tsunami-stricken areas. Among them, the fifth grade donated 576 yuan, which is less than the sixth grade (1/7). How much is the sixth grade donation?
胜利路小学开展为印度洋海啸灾区捐款活动．其中五年级捐款576元，比六年级少捐(1/7)．六年级捐款多少元？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">576 / (6/7)</gadget>
<output>672</output>

<result>672</result>