A has 54 yuan, and B has 36 yuan. If A gives B how much money, they both have exactly the same amount of money?
甲有54元，乙有36元，如果甲把钱拿多少元给乙，他们两人的钱就正好一样多？
<gadget id="calculator">54 + 36</gadget>
<output>90</output>

<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<gadget id="calculator">54 - 45</gadget>
<output>9</output>

<result>9</result>