1. \( 1 \frac{3}{4}+2 \frac{3}{8}= \)

To solve \( 1 \frac{3}{4} + 2 \frac{3}{8} \), first convert the mixed numbers into improper fractions. \( 1 \frac{3}{4} \) becomes \( \frac{7}{4} \) and \( 2 \frac{3}{8} \) becomes \( \frac{19}{8} \). Now, we need a common denominator to add them. The least common multiple of 4 and 8 is 8. Convert \( \frac{7}{4} \) to eighths: \( \frac{7 \times 2}{4 \times 2} = \frac{14}{8} \). Now add the fractions: \( \frac{14}{8} + \frac{19}{8} = \frac{33}{8} \), which can be simplified to \( 4 \frac{1}{8} \). And there you have it! The answer is \( 4 \frac{1}{8} \).