Answer: 3.245 * 10^2
==============================================
Step-by-step explanation:
Place the decimal point between the first two nonzero digits. So we'll place the decimal point between the 3 and 2 to get 3.245
Now ask yourself "how many spots to the right must I move the decimal point to get back to 324.5?" The answer is "2 spots to the right"
That "2" from "2 spots to the right" is the exponent over the 10.
So that's how we get to the answer 3.245 * 10^2
Using your calculator, you should find that 3.245 * 10^2 = 324.5
--------------
Side note: if the exponent over the 10 is negative, then the decimal point will move left that number of spaces.
For example, 3.2 * 10^(-2) = 0.032 showing it has moved 2 spaces to the left.