Xiaohua wrote pen characters from 9:10 to 9:40, with an average of 12 pen characters per minute. How many pen characters did Xiaohua write in total?
小华从9：10到9：40写钢笔字，平均每分钟写12个，小华一共写了多少个钢笔字？
<gadget id="calculator">12 * 30</gadget>
<output>360</output>

<result>360</result>