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Question 189667This question is from textbook Elementary Algebra
: write the number in scientific notation: 1.there are approximately 25,000,000,000,000 red blood cells in the average person's bloodstream.
2.Uranium 236 is radioactive isotope of uranium and has a half -life of 23,420,000.
3.light with a wavelenght of 0.000000586 meter is uyellow in color.
4. Protons have a mass of 0.00000000000000000000000000167 kilograms.
will somebody please explain this to me I really need help. Thank you
This question is from textbook Elementary Algebra
Found 2 solutions by user_dude2008, Edwin McCravy:
Answer by user_dude2008(1862)   (Show Source):
Answer by Edwin McCravy(20059)  (Show Source):
You can put this solution on YOUR website! Edwin's solution:
Rules for changing a number from ordinary notation to scientific notation.
1. Locate the decimal point. If none is showing place the decimal
point on the right end.
25000000000000 has no decimal showing so we put
one on the right end, like this
25000000000000.
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23420000 has no decimal showing so we put
one on the right end, like this 23420000.
0.000000586 shows its decimal.
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0.00000000000000000000000000167 shows its decimal.
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2. Starting at the far left find the first digit that isn't a zero. Put
a red decimal just to the right of that digit. (You can choose another
color, or just make a different looking decimal there, maybe a little
cross mark or something, or you can use a pencil to write one decimal
and a pen to write the other one. But I'll use a red decimal here)
25000000000000. The digit 2 is the first digit that isn't a zero.
So we put a red decimal after that 2, like this:
2.5000000000000.
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23420000. The digit 2 is the first digit that isn't a zero.
So we put a red decimal after that 2, like this:
2.3420000.
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0.000000586 The digit 5 is the first digit that isn't a zero.
So we put a red decimal after that 5, like this:
0.0000005.86
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0.00000000000000000000000000167 The digit 1 is the first digit
that isn't a zero. So we put a red decimal just to the right of
that 1, like this:
0.000000000000000000000000001.67
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3. Count the number of digits between the black decimal and the
red decimal, and that will be the magnitude of the exponent of 10.
2.5000000000000. There are 13 digits
between the black and red decimals. So the magnitude of the exponent
of 10 is 13
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2.3420000. There are 7 digits between the
black and red decimals. So the magnitude of the exponent
of 10 is 7
0.0000005.86 There are 7 digits between the
black and red decimals. So the magnitude of the exponent
of 10 is 7.
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0.000000000000000000000000001.67 There are 27
digits between the black and red decimals. So the magnitude of the exponent
of 10 is 27
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4. Now we determine whether the exponent is positive or negative.
If the black decimal is on the right of the red decimal, the exponent
of 10 is positive.
If the red decimal is on the right of the black decimsl, the exponent
of 10 is negative.
2.5000000000000. The black decimal is
right of the red decimal so the exponent of 10 is positive, and is
therefore +13
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2.3420000. The black decimal is
right of the red decimal so the exponent of 10 is positive, and is
therefore +7
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0.0000005.86 The red decimal is
right of the black decimal so the exponent of 10 is negative, and is
therefore -7
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0.000000000000000000000000001.67 The red decimal is
right of the black decimal so the exponent of 10 is negative, and is
therefore -27.
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5. Erase the black decimal and trim any leading or trailing zeros.
2.5000000000000.
We erase the black decimal at the end
2.5000000000000
Now we trim off all the trailing zeros:
2.5
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2.3420000.
We erase the black decimal at the end
2.3420000
Now we trim off all the trailing zeros:
2.342
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0.0000005.86
We erase the black decimal:
00000005.86
Now we trim off all the leading zeros:
5.86
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0.000000000000000000000000001.67
We erase the black decimal:
0000000000000000000000000001.67
Now we trim off all the leading zeros:
1.67
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6. Finally we put " ×10EXPONENT OF 10 " after it:
2.5 × 1013
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2.342 × 107
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5.86 × 10-7
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1.67 × 10-27
Edwin
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