My mother bought a bag of salt, weighing 500 grams, and ate 20 grams a day for 6 days. How many grams are left?
妈妈买了一袋盐，重500克，每天吃20克，已经吃了6天，还剩多少克？
<gadget id="calculator">20 * 6</gadget>
<output>120</output>

<gadget id="calculator">500 - 120</gadget>
<output>380</output>

<result>380</result>