There are 8 schools participating in a basketball game, and every two schools have to play one game, how many games are needed in total.
有8个学校参加篮球赛，每两个学校都要赛一场，共需赛多少场．
<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>