There are 320 story books in the school library, plus 16 are four times the number of reference books. How many reference books does the school have?
学校图书馆有故事书320本，再加上16本就是工具书的4倍，学校有工具书多少本？
<gadget id="calculator">320 + 16</gadget>
<output>336</output>

<gadget id="calculator">336 / 4</gadget>
<output>84</output>

<result>84</result>