2. (6 points) Calculate: $1+11+21+\cdots+1991+2001+2011=$ $\qquad$
【Analysis】By observation, the difference between two adjacent numbers is 10, which forms an arithmetic sequence, and the sum can be calculated using the Gauss summation formula. This sequence has $(2011-1) \div 10+1=202$ numbers, and then the formula can be applied for calculation.

【Solution】Solution: $1+11+21+\cdots+1991+2001+2011$,
$$
\begin{array}{l}
=(1+2011) \times[(2011-1) \div 10+1] \div 2, \\
=2012 \times 202 \div 2, \\
=203212
\end{array}
$$

The answer is: 203212.