A school cafeteria has 800 kilograms of flour and 9 bags of rice. Each bag weighs 50 kilograms. How many kilograms more flour than rice?
某校食堂有800千克面粉，有9袋大米，每袋重50千克，面粉比大米多多少千克？
<gadget id="calculator">50 * 9</gadget>
<output>450</output>

<gadget id="calculator">800 - 450</gadget>
<output>350</output>

<result>350</result>