Q: How is the number 640,665,419 written in Scientific Notation?
A: 6.40665419 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 640,665,419 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: | 6 | . | 4 | 0 | 6 | 6 | 5 | 4 | 1 | 9 |
| 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 = 6.40665419
b = 8
Now the whole thing:
6.40665419 x 108
Check your work:
108 = 100,000,000 x 6.40665419 = 640,665,419
| 640,665,417 | 640,665,418 | 640,665,420 | 640,665,421 |
| 6.40665417 x 108 | 6.40665418 x 108 | 6.4066542 x 108 | 6.40665421 x 108 |