Wang Hua went to the supermarket to buy a notebook, paid the salesperson 2 yuan, and got back 0.4 yuan. How much did she spend?
王华到超市买了一个笔记本，付给售货员2元，找回0.4元，她花了多少元．
<gadget id="calculator">2 - 0.4</gadget>
<output>1.6</output>

<result>1.6</result>