Bright milk has a net weight of 4.5kg and is priced at 43.2 yuan. Yili milk has a net weight of 5kg and is priced at 47.5 yuan. Which milk is the cheapest? How much is cheaper per kilogram?
光明牛奶净重4.5kg，售价43.2元，伊利牛奶净重5kg，售价47.5元，问哪种牛奶便宜？每千克便宜多少元？
<gadget id="calculator">43.2 / 4.5</gadget>
<output>9.6</output>

<gadget id="calculator">47.5 / 5</gadget>
<output>9.5</output>

<gadget id="calculator">9.6 - 9.5</gadget>
<output>0.1</output>

<result>0.1</result>