what is (8.1 x 10^-9) x (4 x 10^2)?
(8.1 x 10^-9) x (4 x 10^2)?
There are different ways to approach this problem
I would do this problem like this,
8.1 * 4 * 10^-9 * 10^2
32.4 * 10^-7
0.00000324
32.4 with the decimal point moved 7 places to the left (since the exponent is negative)