There are 150 science and technology books in the school library, and the number of story books is four times that of science and technology books. How many more story books than science books are there in the school library?
学校图书馆有科技书150本，故事书的本数是科技书的4倍．学校图书馆里的故事书比科技书多几本？
<gadget id="calculator">150 * 4</gadget>
<output>600</output>

<gadget id="calculator">600 - 150</gadget>
<output>450</output>

<result>450</result>