There are 8 people in the table tennis interest group. If every 2 people play a game, how many games will they play in total?
乒乓球兴趣小组有8人，如果每2人都打一场比赛，共要打多少场．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">7 * 4</gadget>
<output>28</output>

<result>28</result>