Q: How is the number 721,407,660 written in Scientific Notation?
A: 7.2140766 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 721,407,660 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 | 4 | 0 | 7 | 6 | 6 | 0 |
| 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 = 7.2140766 (Please notice any zeroes on the end have been removed)
b = 8
Now the whole thing:
7.2140766 x 108
Check your work:
108 = 100,000,000 x 7.2140766 = 721,407,660
| 721,407,658 | 721,407,659 | 721,407,661 | 721,407,662 |
| 7.21407658 x 108 | 7.21407659 x 108 | 7.21407661 x 108 | 7.21407662 x 108 |