On Sunday, father, mother, and Xiaohang hold a family badminton match. It is stipulated that every two people must play one game. How many games will there be in total? Which games are they? Please record it.
星期天，爸爸、妈妈、小航3人举行家庭羽毛球比赛，规定每2人必赛1场，一共要赛几场？是哪几场？请记录下来．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3 * 1</gadget>
<output>3</output>

<result>3</result>