There are 120 balls in the stationery store. After selling some, there are 48 balls left. How many are sold? (solution with equation)
文具店有皮球120个，卖出一些后，还剩48个，卖出多少个？(用方程解答)
<gadget id="calculator">120 - 48</gadget>
<output>72</output>

<result>72</result>