The school lunch group brought in 500 kilograms of rice. After 5 bags were used, there were 45 kilograms left. How many kilograms of rice per bag on average?
学校伙食团运进大米500千克，用了5袋后，还剩45千克，平均每袋大米多少千克？
<gadget id="calculator">500 - 45</gadget>
<output>455</output>

<gadget id="calculator">455 / 5</gadget>
<output>91</output>

<result>91</result>