Q: How is the number 39,401,821 written in Scientific Notation?
A: 3.9401821 x 107
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 39,401,821 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: | 3 | . | 9 | 4 | 0 | 1 | 8 | 2 | 1 |
| Decimal Count: | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
There are 7 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 = 3.9401821
b = 7
Now the whole thing:
3.9401821 x 107
Check your work:
107 = 10,000,000 x 3.9401821 = 39,401,821
| 39,401,819 | 39,401,820 | 39,401,822 | 39,401,823 |
| 3.9401819 x 107 | 3.940182 x 107 | 3.9401822 x 107 | 3.9401823 x 107 |