3 children play chess, each of them has to play a game with the other two, how many games do they have to play in total?
3个小朋友下棋，每人都要与其他两人各下一盘，他们共要下多少盘．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

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

<result>3</result>