Q: How is the number 721,181,661 written in Scientific Notation?
A: 7.21181661 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 721,181,661 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: | 7 | . | 2 | 1 | 1 | 8 | 1 | 6 | 6 | 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 = 7.21181661
b = 8
Now the whole thing:
7.21181661 x 108
Check your work:
108 = 100,000,000 x 7.21181661 = 721,181,661
| 721,181,659 | 721,181,660 | 721,181,662 | 721,181,663 |
| 7.21181659 x 108 | 7.2118166 x 108 | 7.21181662 x 108 | 7.21181663 x 108 |