There are 8 teams participating in a table tennis match, and every two teams have to compete once. How many games will they hold in total?
一次乒乓球比赛有8个队参加，每两个队要比赛一次，它们一共要举行多少比赛．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">8 * (7/2)</gadget>
<output>28</output>

<result>28</result>