It costs 3.5 yuan per kilogram of apples and 2.7 yuan per kilogram of pears. How much is it more expensive to buy 1 kilogram of apples than 1 kilogram of pears?
每千克苹果3.5元，每千克梨2.7元，买一千克苹果比一千克梨贵多少元．
<gadget id="calculator">3.5 - 2.7</gadget>
<output>0.8</output>

<result>0.8</result>