To find the number of teenagers who attended the game, we can calculate 10% of 4800.
First, we convert the percentage to a decimal:
\[ 10% = 0.10 \]
Next, we multiply 4800 by 0.10:
\[ 4800 \times 0.10 = 480 \]
So, the number of teenagers who attended the game is:
\[ \boxed{480} \]