$3 \frac{1}{4} -1 \frac{3}{8}$ =

Full solution

3 \frac{1}{4} -1 \frac{3}{8}

Convert to Improper Fractions: Convert the mixed numbers to improper fractions. $\newline$ $3 \frac{1}{4}$ is the same as $(3 \times 4 + 1)/4 = \frac{13}{4}$ . $\newline$ $1 \frac{3}{8}$ is the same as $(1 \times 8 + 3)/8 = \frac{11}{8}$ .
Find Common Denominator: Find a common denominator for the two fractions. $\newline$ The common denominator for $4$ and $8$ is $8$ . $\newline$ Convert $\frac{13}{4}$ to an equivalent fraction with a denominator of $8$ by multiplying both the numerator and the denominator by $2$ . $\newline$ $\frac{13}{4} \times \frac{2}{2} = \frac{26}{8}.$
Subtract Fractions: Subtract the two fractions. $\newline$ Now that both fractions have the same denominator, subtract the second fraction from the first. $\newline$ $\frac{26}{8} - \frac{11}{8} = \frac{26 - 11}{8} = \frac{15}{8}$ .
Convert to Mixed Number: Convert the improper fraction back to a mixed number. $\frac{15}{8}$ is the same as $1$ whole and $\frac{7}{8}$ left over, so the mixed number is $1\frac{7}{8}$ .