There are 16 teams in the Zhongzheng Cup Baseball Championship. They are divided into four groups for preliminary rounds. Each group of four teams has to play one game. So how many preliminary rounds will the four groups have in total?
中正杯棒球锦标赛共有16支球队，先分成四个组进行初赛，每组四支球队之间都要比赛一场，那么四个组一共要进行几场初賽？
<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<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>

<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<result>24</result>