Bacteria: Math Lesson: Activity 3 of 3

Now that we’ve had some practice with the powers of 10, let’s write some numbers in scientific notation. Example:

25,000,000 written in scientific notation is 2.5 × 10⁷.

Here's how it’s done:

1. Put a decimal point after the first digit in 25,000,000 to get 2.5000000
2. Count the number of digits after the decimal point. The number 2.5000000 has 7 digits after the decimal.
3. 7 is the exponent, and we always use base 10 in scientific notation, so keep this number in mind: 10⁷
4. Drop all the zeros in 2.5000000 to get 2.5
5. Combine the numbers in step 3 and 4 to get the final form of the scientific notation: 2.5 × 10⁷

To check that the notation is correct:
2.5 × 10⁷ = 2.5 × 10,000,000 = 25,000,000