There is a factory that manufactures small balls, and 6 boxes of small balls are produced, each box contains 100 small balls. The authentic balls weigh 10 grams each, and the defective balls weigh 11 grams each. Since the balls in each box are produced by the same workshop, if there are defective products in one box, all the balls in this box must be defective. Now suppose there is only one box with defective products, using a balance with weights, how to find out this box once by weighing?
有个制造小球的工厂，生产了6箱小球，每个箱子里有100个小球．正品小球每个重10克，次品小球每个重11克．由于每个箱子里的小球由同一车间生产，如果一个箱子里有次品，则这个箱子里的球肯定都是次品．现在假设只有一个箱子里有次品，利用有砝码的天平，如何称一次把这个箱子找出来？
<gadget id="calculator">1 + 2 + 3 + 4 + 5 + 6</gadget>
<output>21</output>

<gadget id="calculator">21 * 10</gadget>
<output>210</output>

<result>210</result>