The sixth grade students donated money to the children in the disaster area. Class 61 donated 500 yuan, Class 62 donated 400 yuan, Class 63 donated the sum of Class 61 and Class 62 (7/9), how much did Class 63 donate?
六年级同学给灾区的小朋友捐款．六一班捐了500元，六二班捐了400元，六三班捐的是六一班和六二班总和的(7/9)，六三班捐款多少元？
<gadget id="calculator">500 + 400</gadget>
<output>900</output>

<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">900 * (7/9)</gadget>
<output>700</output>

<result>700</result>