2. Science often deals with large numbers. The number of hydrogen atoms in a liter of water is almost 70,000,000,000,000,000,000,000,000

3. To write out such large numbers every time you use them would be a lot of trouble. Performing calculations on these numbers would be confusing.

4. Scientific Notation To deal with these large numbers, scientist use scientific notation. All numbers are expressed as two numbers multiplied together. The first number is between 1 and 10 and the second is a power of 10. 200 is written: 2.0 x 10 2

5. Scientific Notation Examples 450,000,000 Step 1 move the decimal point to the left until the number to the left of the decimal point is between 1 and 10. 4.50000000

6. Scientific Notation Examples Determine the size of the exponent. The exponent is equal to the number of places you moved the decimal point. 4.50000000 8 places Step 3: Determine the sign of the exponent. If you move the decimal to the left the sign is positive. 4.5 x 10 8

7. Try these on your paper: 1. 634,000 2. 533 3. 1,900,000 4. 87,000

8. Very Small Numbers.000062 Step 1: Move the decimal point to the right until the number to the left of the decimal point is between 1 and 10 00006.2

9. Very Small Numbers Step 2: Determine the exponent by counting the number of places you moved the decimal. 00006.2 is equal to 5 places Step 3 Determine the sign of the exponent. If you move the decimal to the right, the exponent will be negative: 6.2 x 10 -5

10. Try these on your paper: 5..000053 6..00421 7..000000088 8..012