# Scientific Notation and Computations

1. The exponent shows how many zeros are present to the left of the decimal point.

Examples:
200 = 200. = , 5/1000 = 0.005 = .

2. Notation: Examples:
1 millimeter = micrometers = meters = kilometers
The mass of the Sun is grams = kilograms

3. To multiply in scientific notation, multiply the numbers in front, add the exponents, and (if necessary) change exponent so the number in front is between 1 and 10.

Examples:
What is the mass of a galaxy with Suns?
Answer:   grams = grams.

4. To divide in scientific notation, divide the numbers in front, subtract the exponents, and (if necessary) change exponent so the number in front is between 1 and 10.

Examples:
How many atoms are in your body if your mass is 60 kilograms and a typical atomic mass is kilograms?
Answer: = atoms.
How long would it take for the Space Shuttle to reach the nearest star if it travels at 6 kilometers/second and the star is meters away?
Answer: meters / ( meters/second) = seconds = seconds. Note the change of units between kilometers and meters.

Last updated: Aug 15, 2003 Matthew Bershady