There will be 8 football teams in the London Olympic Games for the final match. If there is a match between two teams, how many games will be played in total?
伦敦奥运会上将有8支足球队进行最后的比赛，如果每两队之间比赛一场，一共要进行多少场比赛．
<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>