The school cafeteria shipped 508 kilograms of rice, and after 7 days of use, there are still 18 kilograms left. How many kilograms are used on average per day?
学校食堂运来大米508千克，用了7天后还剩18千克，平均每天用多少千克？
<gadget id="calculator">508 - 18</gadget>
<output>490</output>

<gadget id="calculator">490 / 7</gadget>
<output>70</output>

<result>70</result>