Xiao Ming and Xiao Liang buy pens together. Ming has 10.2 yuan and Xiao Liang has 8.6 yuan. They put the money together and bought two identical pens. How much should Xiao Liang give back to Xiao Ming?
小明和小亮一起买钢笔，明有10.2元钱，小亮有8.6元钱，他们把钱合在一起正好买了两支同样的钢笔，小亮应该还给小明多少元钱？
<gadget id="calculator">10.2 + 8.6</gadget>
<output>18.8</output>

<gadget id="calculator">18.8 / 2</gadget>
<output>9.4</output>

<gadget id="calculator">10.2 - 9.4</gadget>
<output>0.8</output>

<result>0.8</result>