Kaylee needs to sell 33 boxes of biscuits. So far, she has sold 12 boxes of lemon biscuits to her aunt, 5 boxes of chocolate biscuits to her mother, and 4 boxes of oatmeal biscuits to a neighbor. How many more boxes of biscuits does Kaylee need to sell?
The number of boxes already sold is 12 + 5 + 4 = 
<gadget id="calculator">12+5+4</gadget>
<output>21</output>
21.
Kaylee needs to sell 33 - 21 = 12 more boxes.

<result>12</result>