There are 5 students in a table tennis match, each of them will compete one game, how many games will they compete in total?
有5个同学进行乒乓球比赛，每两人之间都要比一场，一共要比多少场．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 * (1/2)</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>