Teacher Wang took 500 yuan to buy teaching reference materials, bought 16 books, and left 132 yuan. How much is the average price of each reference material?
王老师拿500元去买教学参考资料，买了16本，剩下132元．平均每本参考资料多少元？
<gadget id="calculator">500 - 132</gadget>
<output>368</output>

<gadget id="calculator">368 / 16</gadget>
<output>23</output>

<result>23</result>