Tingting has 30 yuan, 15.6 yuan is used to buy books, and 8.8 yuan is used to buy pens. How much money do you have left?
婷婷有30元钱，买书用去15.6元，买笔用去8.8元．还剩多少元？
<gadget id="calculator">30 - 15.6 - 8.8</gadget>
<output>5.6</output>

<result>5.6</result>