4 students have a table tennis match, and each pair will play one game. How many games will there be in total?
4个同学进行乒乓球比赛，每两人比赛一场，一共要比赛多少场．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">4 * (3/2)</gadget>
<output>6</output>

<result>6</result>