There are 300 kilograms of apples to be packed, 8 boxes have been packed, each box is 35 kilograms, how many kilograms are left?
有300千克苹果需要装箱，已经装了8箱，每箱35千克，还剩多少千克？
<gadget id="calculator">35 * 8</gadget>
<output>280</output>

<gadget id="calculator">300 - 280</gadget>
<output>20</output>

<result>20</result>