Let \( x \) be the total number of people at the stadium. According to the problem, 2% of the attendees were teenagers, which can be expressed mathematically as:
\[ 0.02x = 240 \]
To find \( x \), we can solve the equation by dividing both sides by 0.02:
\[ x = \frac{240}{0.02} \]
Calculating the right side:
\[ x = 240 \div 0.02 = 240 \div \frac{2}{100} = 240 \times \frac{100}{2} = 240 \times 50 = 12000 \]
Thus, the total number of people at the stadium is
\[ \boxed{12000} \]