In a Chinese chess game, a total of 6 players participated in the game. If there is a match between every 2 players, how many games will there be in total?
在一次中国象棋比赛中，一共有6名运动员参加比赛．如果每2名运动员之间都要进行一场比赛，一共要比赛多少场．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<result>15</result>