An exercise book costs 0.50 yuan, and a pen costs 7.40 yuan. How much does it cost to buy an exercise book and a pen?
一个练习本0.50元，一支钢笔7.40元．买一个练习本和一支钢笔一共要付多少元？
<gadget id="calculator">0.5 + 7.4</gadget>
<output>7.9</output>

<result>7.9</result>