Uncle Li and Aunt Wang went to buy the same commemorative stamp. Uncle Li bought 12 and Aunt Wang bought 10. Aunt Wang spent 10 yuan less than Uncle Li. How much is each commemorative stamp?
李叔叔和王阿姨去买同一种纪念邮票．李叔叔买了12张，王阿姨买了10张．王阿姨比李叔叔少花了10元．每张纪念邮票多少元？
<gadget id="calculator">12 - 10</gadget>
<output>2</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<result>5</result>