Choose 5 poker cards, 2 of diamonds, 3 of hearts, 4 of clubs, 5 of spades, and 6 of hearts, and put them on the table with their backs facing up. Choose any two cards to sum. What is the probability that the sum is an even number? Tell me what you think.
选5张扑克牌，方块2、红桃3、梅花4、黑桃5、红桃6，背面朝上放在桌上，任意选两张求和，和是偶数的可能性是多少？说说你的想法．
<gadget id="calculator">4 + 2 + 4</gadget>
<output>10</output>

<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>