1.
Is this student's work correct?
( 9 x 10^3 ) ( 5 x 10^2 ) = ( 9 x 5 ) ( 10^3 x 10^2 )
= 45 x 10^3+2
= 45 x 10^5
A. Yes. The student rewrote the problem and then multiplied correctly. ***
B. No. The student should have changed the scientific notation to expanded form first.
2.
Convert to expanded form.
1.23025 x 10^2
A. 12.3025 ***
B. 123.025
C. 12, 305
3.
Use scientific notation to rewrite the number.
0.000034
A. 3.4 x 10^5 ***
B. 3.4 x 10^7
C. 34 x 10^8
Please check my answers! <3
1. the answer of 45 x 10^5 is correct but in scientific form should be
4.5 x 10^6
2.
1.23025 x 10^2 = 123.025 , I moved the decimal 2 places
3.
0.000034 = 3.4 x 10^-5
how many places did I move the decimal, the negative exponent on the 10 shows we have a "small" number
So for one, would my answer be right or wrong? Oof
Two - ah! i see! lol i was thinking it was that one as well
Three - I don't have an option for any of them negative, which is why i am confused on that one:(
I repeat my answer I gave before:
1.
"the answer of 45 x 10^5 is correct but in scientific form should be
4.5 x 10^6 "
A true scientific number has its decimal after ONE digit then multiplied by a power of 10
e.g. 5.6 x 10^4
e.g. 1.9 x 10^-8
in #3, then they have a misprint or typo, the exponents will be negative
I summarize my answers:
1. the answer is correct, BUT it is not in scientific notation. As I stated at the beginning
2. B, as I stated at the beginning
3. The given choices do not contain the correct answer
the correct answer is : 0.000034 = 3.4 x 10^-5
1. The student's work is incorrect. The correct way to multiply two numbers in scientific notation is to multiply the coefficients (the numbers in front of the powers of 10) and add the exponents. So, in this case, the correct calculation would be:
(9 x 10^3) (5 x 10^2) = (9 x 5) (10^3 x 10^2) = 45 x 10^(3+2) = 45 x 10^5
Therefore, the student made an error in the last step, where they incorrectly added the exponents instead of multiplying them.
2. To convert a number in scientific notation to expanded form, you multiply the coefficient by the power of 10. So, in this case:
1.23025 x 10^2 = 1.23025 multiplied by 10 raised to the power of 2
= 12.3025
Therefore, the correct conversion is 12.3025.
3. To rewrite the number 0.000034 in scientific notation, you need to move the decimal point to the right so that there is only one non-zero digit to the left of the decimal point. This can be achieved by multiplying it by a power of 10. In this case, we can move the decimal point 5 places to the right:
0.000034 = 3.4 x 10^(-5)
Note that we express the power of 10 as -5 instead of 5, since we moved the decimal point to the right.
Therefore, the correct scientific notation for 0.000034 is 3.4 x 10^(-5).