Xiaozhen has 18 yuan, Huanhuan has 10 yuan, how much money Xiaozhen gives to Huanhuan, they both have the same amount of money.
小珍有18元钱，欢欢有10元钱，小珍给欢欢多少元钱，两人就有同样多的钱．
<gadget id="calculator">18 + 10</gadget>
<output>28</output>

<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">18 - 14</gadget>
<output>4</output>

<result>4</result>