Obviously, I originally had 5.1 yuan, but I spent 2.5 yuan to buy the picture book. How much money is left now?
明明原来有5.1元钱，买图画本用了2.5元，现在还剩多少元钱？
<gadget id="calculator">5.1 - 2.5</gadget>
<output>2.6</output>

<result>2.6</result>