1. The problem is to evaluate the expression $2 \times r^n$ for $n=3$ and $r=2$. 2. Substitute the given values into the expression: $2 \times 2^3$. 3. Calculate the exponent first: $2^3 = 2 \times 2 \times 2 = 8$. 4. Multiply by 2: $2 \times 8 = 16$. 5. Therefore, the value of the expression $2 \times r^n$ when $n=3$ and $r=2$ is $16$.