Q: How is the number 221,321,665 written in Scientific Notation?
A: 2.21321665 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 221,321,665 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 | . | 2 | 1 | 3 | 2 | 1 | 6 | 6 | 5 |
| 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 = 2.21321665
b = 8
Now the whole thing:
2.21321665 x 108
Check your work:
108 = 100,000,000 x 2.21321665 = 221,321,665
| 221,321,663 | 221,321,664 | 221,321,666 | 221,321,667 |
| 2.21321663 x 108 | 2.21321664 x 108 | 2.21321666 x 108 | 2.21321667 x 108 |