Mom bought 1.8 kilograms of fish at the vegetable market, handed it to the salesperson for 20 yuan, and got back 8.3 yuan. How much is it per kilogram of fish?
妈妈在菜市场买了1.8千克鱼，交给售货员20元，找回8.3元．每千克鱼多少钱？
<gadget id="calculator">20 - 8.3</gadget>
<output>11.7</output>

<gadget id="calculator">11.7 / 1.8</gadget>
<output>6.5</output>

<result>6.5</result>