Xiaohong has 42 stamps, and Xiaoming has 15 fewer stamps than Xiaohong. How many stamps do they have in total?
小红有42张邮票，小明的邮票张数比小红少15张，他们一共有邮票多少张？
<gadget id="calculator">42 - 15</gadget>
<output>27</output>

<gadget id="calculator">27 + 42</gadget>
<output>69</output>

<result>69</result>