It costs 2.5 yuan to buy a bottle of beverage, and 2.2 yuan per bottle if purchased in a box (24 bottles). How much is it cheaper to buy in a box than to buy in pieces?
买一瓶饮料需2.5元，如果成箱(24瓶装)购买则每瓶2.2元．成箱购买比零买每箱便宜多少元？
<gadget id="calculator">2.5 - 2.2</gadget>
<output>0.3</output>

<gadget id="calculator">0.3 * 24</gadget>
<output>7.2</output>

<result>7.2</result>