Bella bought stamps at the post office. Some of the stamps had a snowflake design, some had a truck design, and some had a rose design. Bella bought 11 snowflake stamps. She bought 9 more truck stamps than snowflake stamps, and 13 fewer rose stamps than truck stamps. How many stamps did Bella buy in all?
The number of truck stamps is 11 + 9 = 
<gadget id="calculator">11+9</gadget>
<output>20</output>
20.
The number of rose stamps is 20 - 13 = 
<gadget id="calculator">20-13</gadget>
<output>7</output>
7.
Bella bought 11 + 20 + 7 = 
<gadget id="calculator">11+20+7</gadget>
<output>38</output>
38 stamps in all.

<result>38</result>