Write $1 \frac{7}{13}$ as an improper fraction.

Step 1 ：Write $1 \frac{7}{13}$ as an improper fraction.

Step 2 ：An improper fraction is a fraction where the numerator (top number) is greater than the denominator (bottom number).

Step 3 ：To convert a mixed number to an improper fraction, we multiply the whole number by the denominator of the fraction, then add the numerator. This becomes the new numerator, while the denominator remains the same.

Step 4 ：Let's start with the whole number 1, the numerator 7, and the denominator 13.

Step 5 ：We multiply the whole number by the denominator: $1 \times 13 = 13$.

Step 6 ：Then we add the numerator: $13 + 7 = 20$.

Step 7 ：This becomes the new numerator, so the improper fraction is $\frac{20}{13}$.

Step 8 ：Final Answer: The improper fraction is $\boxed{\frac{20}{13}}$.