Fill two identical glass bottles with water and weigh them to be 6 kg. Take out one of the bottles, pour out half of the water, put it back on the scale, and the weight is 5 kg. How much does a glass bottle weigh in kilograms?
把两个相同的玻璃瓶都装满水，称得他们得重量是6千克．拿出其中的一瓶，把水倒掉一半，再放回称上，称得重量是5千克．一个玻璃瓶重多少千克．
<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<result>1</result>