1. (10 points) $1 \frac{1}{2}+3 \frac{3}{4}+5 \frac{5}{6}+7 \frac{7}{8}=$
【Analysis】According to the associative law and commutative law of addition, perform the calculation.
【Solution】Solution: $1 \frac{1}{2}+3 \frac{3}{4}+5 \frac{5}{6}+7 \frac{7}{8}$
$$
\begin{array}{l}
=1+\frac{1}{2}+3+\frac{3}{4}+5+\frac{5}{6}+7+\frac{7}{8} \\
=(1+3+5+7)+\left(\frac{1}{2}+\frac{3}{4}+\frac{5}{6}+\frac{7}{8}\right) \\
=16+2 \frac{23}{24} \\
=18 \frac{23}{24}
\end{array}
$$

Therefore, the answer is: $18 \frac{23}{24}$.