Zhang Mei wants to send postcards to her pen pals. She has 138 postcards, and each pen pal sends 6. How many pen pals does Zhang Mei have?
张梅想给笔友寄明信片，她有138张明信片，每个笔友寄6张．张梅有多少个笔友？
<gadget id="calculator">138 / 6</gadget>
<output>23</output>

<result>23</result>