In a table tennis match, there are 7 players. If there is a match between every two players, how many games will there be in total?
在一次乒乓球比赛中，共有7名运动员．如果每两名运动员之间都要进行一次比赛，一共要比赛多少场．
<gadget id="calculator">7 - 1</gadget>
<output>6</output>

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

<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<result>21</result>