The fifth grade students donated a total of 640 yuan, and the fourth grade donated more (1/8) than the fifth grade. How much did the fourth grade students donate?
五年级同学一共捐款640元，四年级捐的比五年级多(1/8)，四年级同学捐款多少元？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 + (1/8)</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">640 * (9/8)</gadget>
<output>720</output>

<result>720</result>