The grocery store originally had 400 kilograms of melon seeds, sold 310 kilograms, and brought in 3 bags of 80 kilograms each. How many kilograms of melon seeds does this store have?
食品店原来有400千克瓜子，卖出310千克，又运进来3袋，每袋80千克，这个商店现有瓜子多少千克？
<gadget id="calculator">400 - 310</gadget>
<output>90</output>

<gadget id="calculator">80 * 3</gadget>
<output>240</output>

<gadget id="calculator">90 + 240</gadget>
<output>330</output>

<result>330</result>