On Xiaoxiao's birthday, 3 children came to the house, father, mother and each child shook hands once, how many times should they shake hands in total.
笑笑生日那天，家里来了3位小朋友，爸爸、妈妈和每一位小朋友握一次手，一共要握多少次手．
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>