Four students, Xiaohua, Xiaoming, Xiaoqing, and Xiaoyan, play chess. It is stipulated that each of them should play a game, and how many games should they play in total.
小花、小明、小青、小燕4位同学下象棋，规定每两人都要下一盘，一共要下多少盘．
<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>