Final answer:
The total number of paper airplanes Fiona and her family made can be represented by the numerical expression: (12 + 8) x 2 + 3.
Step-by-step explanation:
The total number of paper airplanes Fiona and her family made can be represented by the numerical expression: (12 + 8) x 2 + 3. The expression uses parentheses to indicate that the addition of 12 and 8 should be done first. Then, the result is multiplied by 2 to account for the doubling of planes in the afternoon. Finally, 3 is added to account for the extra planes made by Fiona's little brother. This expression represents the total number of paper airplanes made by Fiona and her family without simplifying it.