To get what 4.1x10^3 is equal to you move the decimal point to the right three times. This leaves you with 4,100. To get what 2.0x10^3 is equal to, you move the decimal point to the right three times. This leaves you with 2,000. 4,100 x 2,000 is 8,200,000. Then move the decimal to the left until it is behind the 8. In order to do this, you would have to move the decimal point 6 times. So the final answer is 8.2 x 10^6.
