The cafeteria of Jiupu Experimental Primary School brought in 50 bags of rice, with an average of 3 bags per day. How many bags of rice are left after a week?
旧铺实验小学食堂运进50袋大米，平均每天吃3袋．一个星期后还剩下多少袋大米？
<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">50 - 21</gadget>
<output>29</output>

<result>29</result>