Xiaohua used to have some stamps, but this year he collected 20 more. After giving 15 to Xiaohong, there are 36 stamps left. How many stamps did Xiao Hua originally have?
小华原来有一些邮票，今年又收集了20枚，送给小红15枚后，还剩36枚．小华原来有邮票多少枚？
<gadget id="calculator">36 - 20</gadget>
<output>16</output>

<gadget id="calculator">15 + 16</gadget>
<output>31</output>

<result>31</result>