Xiaohong spent 3.7 yuan to buy the notebook, and there is 6.3 yuan left. How much did Xiaohong originally have?
小红买笔记本用了3.7元，还剩6.3元，小红原来有多少元．
<gadget id="calculator">3.7 + 6.3</gadget>
<output>10</output>

<result>10</result>