Answer
$$2.0\times 10^{1}$$
Work Step by Step
In scientific notation, the number of significant digits is the number of digits in the leading number between $1$ and $10$. The final answer should have the same number of significant digits as the least number of significant digits in any of the numbers involved in the division:
$6.48\times 10^{6}$ has $3$ significant digits
$3.2\times 10^{5}$ has $2$ significant digits.
Therefore, the final answer should be rounded to have $2$ significant digits.
Rearrange factors and divide:
$$\frac{6.48\times 10^{6}}{3.2\times 10^{5}}=\bigg(\frac{6.48}{3.2}\bigg)\bigg(\frac{10^{6}}{10^{5}}\bigg)=2.0\times 10^{1}.$$
