To find the area of a Canadian football field, we first need to calculate the area by adding the additional area of 3,350 square yards to the area of the American football field (6.4×10³ square yards).
First, convert 3,350 square yards to scientific notation:
\[ 3,350 = 3.35 \times 10^3 \text{ square yards} \]
Now we can calculate the area of the Canadian football field:
\[ \text{Area of Canadian football field} = (6.4 \times 10^3) + (3.35 \times 10^3) \]
To add these two areas, we can sum their coefficients since they are already in the same power of ten:
\[ = (6.4 + 3.35) \times 10^3 \] \[ = (9.75) \times 10^3 \]
Now, this is in the form of scientific notation. Therefore, the area of a Canadian football field is:
\[ \boxed{9.75 \times 10^3} \text{ square yards} \]