Mom brought 300 yuan to the supermarket and bought 9 bags of rice, and got 30 yuan back. How much is each bag of rice?
妈妈带300元到超市买了9袋大米，找回30元，每袋大米多少元？
<gadget id="calculator">300 - 30</gadget>
<output>270</output>

<gadget id="calculator">270 / 9</gadget>
<output>30</output>

<result>30</result>