Xiao Ming spent 6.6 yuan on a pencil case and 40 cents on an eraser. How much did he spend in total?
小明买了一个铅笔盒用去6.6元，买了一块橡皮用去了4角，他一共用去了多少元．
<gadget id="calculator">6.6 + 0.4</gadget>
<output>7</output>

<result>7</result>