Scientific Notation

1. Scientific Notation

2. Basics • All numbers written in scientific notation will look like this: n x 10a n = a number that is greater than or equal to one and less than 10 1 ≤ n < 10 a = the number of times the decimal moved when the number was in standard form.The number in standard form determines whether the exponent is positive or negative.

3. Positive Exponent • The exponent will be positive if the number in standard form is greater than 1. • Example: 549.3This is a number greater than 1. To write this in scientific notation, move the decimal point two (2) times to the left to make a number less than 10 but greater than or equal to 1. 5.493 5.493 X 102 Now the power of 10 that goes with this number will have a positive exponent of 2 because we moved the decimal two times and the number was greater than 1 in standard form.

4. Negative Exponent • The exponent will be negative if the number in standard form is less than 1. • Example: .000298 This is a number that is less than 1. To write this in scientific notation move the decimal four (4) times to the right in order to get a number less than 10 and greater than or equal to 1. 2.98 2.98 x 10-4 The power of 10 that goes with this number will have a negative exponent because the number in standard form was less than 1.

5. Practice Problems • Write the following numbers in scientific notation. • 12.9 2. 999 3. .000007 • .056 5. 18 6. .000288 • Write the following numbers back in standard form. • 4.3 x 10-3 2. 9.825 x 102 3. 5.04 x 10-1 4. 1.0001 x 105 5. 3.77 x 10-4 6. 8.1 x 103