Teacher Wang bought two reference books. "Primary Mathematics Teaching Guide" is 12.36 yuan, which is 4.25 yuan more than "Mathematics Handbook". How much does Mr. Wang pay?
王老师买了两本参考书．《小学数学教学指导》12.36元，比《数学手册》多4.25元．王老师应付多少钱？
<gadget id="calculator">12.36 - 4.25</gadget>
<output>8.11</output>

<gadget id="calculator">8.11 + 12.36</gadget>
<output>20.47</output>

<result>20.47</result>