I need someone to EXPLAIN how to get the answers to these scientific notations?

Question

write each number in scientific notation

1) -0.0128



write each number without exponents


8.9 x 10^6

Answer 1

Hi,
Prob #1
Numbers expressed with scientific notation have one significant digit to the left of the decimal point. So, to convert the first number to scientific notation do this:
1) Move the decimal point to the right two places to get
1.28
2) The number has gotten larger, so we must multiply it by an exponent to bring it back to its beginning value.
1.28 x 10^(-2).
We moved it two decimal places and since we moved to the right, the exponent must be negative to make the number smaller.

Prob #2:
We want to write the number without exponents. So, since the exponent is positive 6, the decimal point has been moved 6 places to the left. So, to write it without an exponent, we move the decimal point 6 places to the right, adding sufficient zeros.
8900000
So, we moved the decimal six places to the right, but we don't include the decimal point if there are no digits to it's right.

Hope this helps.
FE

Answer 2

scientific notation is simply decimal places. the 10 to the whatever power tells you how many places to move the decimal place. a negative number to the left, a positive number to the right.
so -0.0128 needs the decimal place to be moved to the right 2 places. so the final number is -1.28x10^-2.
the second one the 10^6 means move the decimal 6 places to the right so it gives you 8900000.