Mom bought 8 kilograms of rice with 20 yuan, and got back 4 yuan. How much is it per kilogram of rice?
妈妈用20元钱买了8千克大米，找回4元，每千克大米多少元？
<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<gadget id="calculator">16 / 8</gadget>
<output>2</output>

<result>2</result>