To find out how many miles Sonny walks after seven days, we can multiply the distance he walks each day by the number of days:
\[ \text{Distance walked in seven days} = \left(\frac{2}{3} \text{ miles/day}\right) \times 7 \text{ days} \]
Calculating this:
\[ \frac{2}{3} \times 7 = \frac{2 \times 7}{3} = \frac{14}{3} \text{ miles} \]
To convert \(\frac{14}{3}\) into a mixed number:
\[ \frac{14}{3} = 4 \frac{2}{3} \text{ miles} \]
Therefore, Sonny walks \(\frac{14}{3}\) miles, or \(4 \frac{2}{3}\) miles, after seven days.