Q: How is the number 12,721,991 written in Scientific Notation?
A: 1.2721991 x 107
The purpose of scientific notation is for scientists to write very large, or very small, numbers with ease.
Calculating scientific notation for a positive integer is simple, as it always follows this notation:
a x 10b
Follow the steps below to see how 12,721,991 is written in scientific notation.
To find a, take the number and move a decimal place to the right one position.
Now, to find b, count how many places to the right of the decimal.
| New Number: | 1 | . | 2 | 7 | 2 | 1 | 9 | 9 | 1 |
| Decimal Count: | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
There are 7 places to the right of the decimal place.
Building upon what we know above, we can now reconstruct the number into scientific notation.
Remember, the notation is: a x 10b
a = 1.2721991
b = 7
Now the whole thing:
1.2721991 x 107
Check your work:
107 = 10,000,000 x 1.2721991 = 12,721,991
| 12,721,989 | 12,721,990 | 12,721,992 | 12,721,993 |
| 1.2721989 x 107 | 1.272199 x 107 | 1.2721992 x 107 | 1.2721993 x 107 |