Before eating, there are 5 children who put both hands on the table, 6 children who only put their left hand on the table, and 7 children who only put one hand on the table. several? How many
吃饭前，两只手放在桌上的小朋友有5个，只把左手放在桌上的小朋友有6个，只把一只手放在桌上的小朋友有7个，你说吃饭的小朋友有几个？多少
<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<result>12</result>