The store originally had 84 kilograms of white sugar, but another 28 kilograms were shipped in. After selling for one day, there were still 68 kilograms left. How many kilograms were sold on that day?
商店原来有84千克白糖，又运来28千克，卖了一天后还剩68千克，这天卖出多少千克？
<gadget id="calculator">28 - 68</gadget>
<output>-40</output>

<gadget id="calculator">84 + (-40)</gadget>
<output>44</output>

<result>44</result>