The grain store shipped 420 bags of rice, 30 bags less than the amount of flour shipped. How many bags of flour are shipped? (Write out the quantitative relationship and use the equation to solve it)
粮店运来大米420袋，比运来的面粉少30袋．运来面粉多少袋？(写出数量关系是并用方程解)
<gadget id="calculator">420 + 30</gadget>
<output>450</output>

<result>450</result>