The net weight of a bottle of water is 3 kg, and the weight of the bottle is 500 g, what is the actual weight of the water?
一瓶水净重量是3千克，瓶子重500克，求水的实际重量？
<gadget id="calculator">3 * 1_000</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 - 500</gadget>
<output>2_500</output>

<result>2_500</result>