Part of a bag of washing powder is used up, leaving 350 grams. The original weight of this bag of washing powder is 500 grams. How many grams are used?
一袋洗衣粉用去一部分，剩下350克，这袋洗衣粉原来重500克，用去了多少克？
<gadget id="calculator">500 - 350</gadget>
<output>150</output>

<result>150</result>