A bottle of fruit juice weighs exactly 1 kg, and the bottle weighs 160 grams. What is the net weight of the bottle of juice in grams?
一瓶果汁正好重1千克，瓶子重160克，这瓶果汁的净含量是多少克．
<gadget id="calculator">1 * 1_000</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 - 160</gadget>
<output>840</output>

<result>840</result>