The school carried out "Learn from Lei Feng and do good deeds with 4 people group activities". The number of participants is: 21 boys and 27 girls. How many groups are there in total?
学校开展"学雷锋做好事4人小组活动"．报名参加人数是：男生21人，女生27人．一共可分成几个小组？
<gadget id="calculator">21 + 27</gadget>
<output>48</output>

<gadget id="calculator">48 / 4</gadget>
<output>12</output>

<result>12</result>