The school will add two new books to the library, 3 sets of each. It is known that each set of "Children's Encyclopedia" is 125 yuan, and each set of "Mathematics Fun Questions" is 18 yuan. How much more does it cost to buy "Children's Encyclopedia" than "Math Fun Problems"?
学校要为图书馆增添两种新书，每种3套．已知《儿童百科》每套125元，《数学趣味题》每套18元．买《儿童百科》比买《数学趣味题》要多花多少钱？
<gadget id="calculator">125 - 18</gadget>
<output>107</output>

<gadget id="calculator">107 * 3</gadget>
<output>321</output>

<result>321</result>