Uncle Li bought 5 pieces of soap at 1.56 yuan each. He gave the salesman 10 yuan, how much should he get back?
李叔叔买了5块香皂，每块1.56元．他给了售货员10元钱，应找回多少元？
<gadget id="calculator">1.56 * 5</gadget>
<output>7.8</output>

<gadget id="calculator">10 - 7.8</gadget>
<output>2.2</output>

<result>2.2</result>