In the labor class, the students learn to stir-fry vegetables. About 0.006 grams of salt is needed for every kilogram of green vegetables. Now they want to stir-fry 500 grams of green vegetables, how many grams of salt should be added?
劳动课上，同学们学习炒菜，每1千克青菜中大约需食盐0.006克，现在要炒500克青菜，大约放食盐多少克？
<gadget id="calculator">500 / 1_000</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">0.006 * (1/2)</gadget>
<output>0.003</output>

<result>0.003</result>