Scientific Notation???? HELP!!!!! =[?

9. the answer is d.

reason: .0062 times 10^2 is just moving .0062 to the left two spaces to make .62 Then when you look at the answers .62 times 10^0 (which is 1) is also .62

13. the answer is c

reason: when you divide 8.1 over 9 is equal to 9/10 or .9

10^ over 10^-3 is 10^5 since two minuses cancel each other out (division is a form of exponent sunbtraction)

so look we have .9 times 10^5 so why do i say c

because if multiply .9 by ten and take out that ten from the 10^5 you get 9 times10^4

16. the answer is a

you multiply 2 times 4 and 10^5 times 10^-8

you get 8 times 10^-3

Trust me on this one i even used a calculator to check

I hope i helped and please give me the points if im the right answer

Just put it into terms you can use:

.0062*10*10 = .0062*100 = move the decimal two places to the right because there’s two zeros in 100 and it’s positive.

= .62 Then find the answer that can describe this:

*B. 6.2*10^-1 THIS ONE****** – because the -1 (or .10) means to move the decimal one place to the left = .62

3.) (8.1*10^2)/(9.0*10^-3)

So: 810/.009 The 10^2 tells you to move the decimal two places to the right (positive #) & the 10^-3 makes you move the decimal to the left 3 places from where it is in 9.0

Then: 810/.009 = 90000 which is the same as: C

*C. 9.0*10^4= 90000 THIS ONE**********

PS you can look at .009 as 9/1000. Which is really easy to use in this fraction to find the value. 810/9/1000 is really 810*1000/9. Because the fraction is under that division sign, just multiply by it’s opposite 1000/9 🙂

6.) (2*10^5)(4*10^-8)

So: (200000)(.00000004) this is because 10^5 tells you 5 decimal places to the right from where it is 2., and 10^-8 moves the decimal to the left 8 places from 4. Don’t forget to start from this place behind the 4 since there’s no decimal actually shown, then move over 8 places.

Then: (200000)(.00000004) = .008

a. 8.0*10^-3= 0.008

13. is B(8.1*10^2)/(9.0*10^-3)

8.1 x 9 = 72.9 <<<< 7.3 x 10^-1<<<<-3+2=-1 16. is A 2 x 4 =8 -8+5=-3<< the exponents added together 8.0 x 10^-3

b. 6.2*10^-1…. if you hopped the decimal point in 6.2 over one digit to the left

Answer is B.

13.) (8.1*10^2)/(9.0*10^-3)

8.1 / 9.0 = 0.9 = 9 x 10^-1

and 10^2 / 10^-3 = 10^2 x 10^3 = 10^5

so…

(8.1*10^2)/(9.0*10^-3) = 9 x 10^-1 x 10^5 = 9 x 10(-1+5) = 9 x10^4

c. 9.0*10^4= 90000

Answer is C.

16.) (2*10^5)(4*10^-8)

= 2 * 4 * 10^5 * 10^-8 = 8 * 10^(5-8) = 8 * 10^-3

a. 8.0*10^-3= 0.008

Answer is A.

13) you multiply the main numbers and subtract the exponents so the answer is C

16) is A because you add the exponents so the answer becomes 8 and the exponents equal -3