The fruit shop shipped 9 boxes of pears and 9 apples each. The total weight of the pears was 270 kg, and the total weight of the apples was 180 kg. How much is each carton of apples lighter than each carton of pears?
水果店运来梨和苹果各9箱，梨共重270千克，苹果共重180千克．每箱苹果比每箱梨轻多少千克？
<gadget id="calculator">270 - 180</gadget>
<output>90</output>

<gadget id="calculator">90 / 9</gadget>
<output>10</output>

<result>10</result>