The school library newly purchased 280 fairy tale books and story books each. Each fairy tale book is 13.8 yuan, and each story book is 15.2 yuan. How much did it cost to buy these books?
学校图书室新购进童话书和故事书各280本．童话书每本13.8元，故事书每本15.2元．购进这些书一共需要多少钱？
<gadget id="calculator">13.8 * 280</gadget>
<output>3_864</output>

<gadget id="calculator">15.2 * 280</gadget>
<output>4_256</output>

<gadget id="calculator">3_864 + 4_256</gadget>
<output>8_120</output>

<result>8_120</result>