To Garrek99: We are working with a scale here, not a balance. It may be used once. If you choose to weigh all ten bags, these bags must be placed on the scale, and there is no reason why they cannot be placed on the scale one at a time. As they are placed on the scale, notice how much the weight reading increases. Of course, this scale could have a blank lcd readout that will display its one and only reading to you when you hit the "ready" button. Then this would not work. Then it's back to the powers of two.