Q: How is the number 205,456,721 written in Scientific Notation?
A: 2.05456721 x 108
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 205,456,721 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: | 2 | . | 0 | 5 | 4 | 5 | 6 | 7 | 2 | 1 |
| Decimal Count: | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
There are 8 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 = 2.05456721
b = 8
Now the whole thing:
2.05456721 x 108
Check your work:
108 = 100,000,000 x 2.05456721 = 205,456,721
| 205,456,719 | 205,456,720 | 205,456,722 | 205,456,723 |
| 2.05456719 x 108 | 2.0545672 x 108 | 2.05456722 x 108 | 2.05456723 x 108 |