At the end of a sports competition, 7 award-winning athletes want to shake hands. If every 2 people shake hands once, how many times do they shake hands in total?
一次体育比赛结束时，7名获奖运动员想到握手，如果每2人握一次手，共握几次手？
<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">6 * (7/2)</gadget>
<output>21</output>

<result>21</result>