Xiaoguang went to the sporting goods store to buy 3 footballs and paid 200 yuan, 50 yuan for each football. How much should the salesperson aunt give Xiaoguang?
小光到体育用品商店买3个足球付了200元，每个足球50元．售货员阿姨应该找给小光多少钱？
<gadget id="calculator">50 * 3</gadget>
<output>150</output>

<gadget id="calculator">200 - 150</gadget>
<output>50</output>

<result>50</result>