1. (8 points) The calculation result of the expression $(1+3+5+\cdots+89)-(1+2+3+\cdots+63)$ is $\qquad$
【Solution】Solution: $(1+3+5+\cdots+89)-(1+2+3+\cdots+63)$
$$
\begin{array}{l}
=(1+89) \times[(89-1) \div 2+1] \div 2-(1+63) \times 63 \div 2 \\
=90 \times 45 \div 2-64 \times 63 \div 2 \\
=2025-2016 \\
=9
\end{array}
$$

Therefore, the answer is: 9.