There are 36 kilograms of apples in the store, 50 kilograms are shipped and 47 kilograms are sold, how many kilograms are left?
商店里有36千克苹果，运来50千克又卖出47千克，还剩多少千克．
<gadget id="calculator">50 - 47</gadget>
<output>3</output>

<gadget id="calculator">36 + 3</gadget>
<output>39</output>

<result>39</result>