On a balance, put a box of glass balls on one side, (1/4) box of glass balls and nine weights of 50 grams on the other side. The balance is balanced. How much does a box of glass balls weigh?
在一架天平上，一边放上一盒玻璃球，另一边放上(1/4)盒玻璃球和9个50克的砝码，天平是平衡的，一盒玻璃球有多重？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">9 / (3/4)</gadget>
<output>12</output>

<gadget id="calculator">50 * 12</gadget>
<output>600</output>

<result>600</result>