Scientific notation?

(1.32x10^-5 )(3.2x10^4 )^2 can someone please explain how to do this my answer was incorrect.

first i multiplied 1.32 and 3.2 =4.224
then i multiplied exponents 4 and 2 = 8, and added -5 exponent with 8 = 3
once i rounded to the sig fig i my final answer was 4.2x10^3 but it is incorrect. please help!


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Most Helpful Guy

  • Been a few decades for me, but you need to apply the exponent ^2 to the 3.2 before multiplying that term times the 1.32. After you have that then you can figure in the exponents 4 and 2 equaling 8 and added to the -5 equals 3. You just did not apply the ^2 to the 3.2

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    • THANK YOU!!!

    • You are welcome. Like I said, I had to clean out the cobwebs in my brain to remember this.

What Guys Said 5

  • Square 3.2 as well

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  • PEMDAS. exponents before multiplication division addition or subtraction. You need to do everything inside the parenthesis first. So do 1.32x10^-5 first. Then do 3.2x10^4. whatever you get with 3.2x10^4 use the exponent of 2 on that. Then take that answer and multiply it to the 1.32x10^-5 power's answer.

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    • you can't simplify whats inside the parenthesis? its written in scientific notation its not 3.2 times 10 to the fourth

    • I always take it out of scientific notation and then solve and then put back into scientific notation at the end.

  • Did you remember the ^2 at the end?

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    • Work out the brackets first

      1.32 X 3.2 = 4.224
      Exponent 10^--5 + 10^4 = 10^-1
      So first part with brackets multiplyed is
      4.224 X 10^-1
      Then square the result with the ^2 gives 17.842 X 10^-2 ( to 3 d. p.)

      OMG I've just sat a-level maths exam. If I'm wrong here, there's no hope for me!!

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    • AAAHH! I think I'm wrong! RTBQ!!

    • Should be 3.2^2 = 10.24 exponent 10^8
      10.24 X 1.32 = 13.5168 exponent 10^3

      I'm sure this is correct. Previous was rubbish! Sorry!

  • You do realize this literally just means 0.0000132 * 32000 * 32000 right? It is essentially just 1.32 * 10^-5 * (3.2)^2 * (10^4)^2 which is 1.32 * (3.2*3.2) * 10^(-5 + 8)

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    • so what would be the answer?

    • ... That was meant to be - 5 + 8 but apparently emoticons are preferred over math. Evaluate the answer with a calculator, I don't have one at hand right now

    • Well it claims to be 13.5168 * 10^3 which is 1.35168 * 10^4 I might double check it later though

  • Scientists notation is not calculated that same as how you would do follow a PEMDAS or FOIL acronym procedure. Scientific notation is in it's presented one way multiplying form form already and has been calculated already past procedure. So (1.32•10^-5)•(3.2•10^4) raise to the second power. So multiply the answer by itself... Covert it back to scientific notation because you might get lots of zeros placement digits.

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What Girls Said 2

  • You can simply put that in your calculator to get the answer, but if you want to break it down, that would be:

    (1.32 x 10^-5) (3.2 x 10^4)^2
    = (1.32 x 10^-5) (3.2^2 x 10^8)
    = (1.32 x 10^-5) (10.24 x 10^8)
    = (1.32 x 10.24) [10^(-5+8)]
    = 13.5168 x 10^3

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  • Use enough parenthesis. I use to mess up by forgetting parenthesis.

    Also, make sure you're using pemdas.

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    • how does PEMDAS apply when multiplying between scientific notation? you're not simplifying whats inside the parenthesis

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    • unfortunantly no if i had hints i wouldn't be asking for help on this site. lol

    • I don't have a calculator :C
      Usually, I do if a few ways until I get the correct answer, then write down what to do next time. Also, wish I could be more help but I really should be asleep.

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