Fengshou Granary sells a certain kind of high-quality rice at a discount. The price per kilogram is 5.68 yuan. My mother bought 20 kilograms and paid the salesperson 120 yuan. How much yuan is left?
丰收粮仓优惠销售某种优质大米，每千克的价格是5.68元，妈妈买了20千克，付给售货员120元，还剩下多少元？
<gadget id="calculator">5.68 * 20</gadget>
<output>113.6</output>

<gadget id="calculator">120 - 113.6</gadget>
<output>6.4</output>

<result>6.4</result>