Tongren City held a basketball game for primary school students. The 4 participating schools competed with each other. How many games will there be in total?
铜仁市举行小学生篮球比赛，4个参赛学校每两个学校比一场，一共要比多少场．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<result>6</result>