3-9 Operations: Scientific Notation - We learned how to use scientific notation to express very large and very small numbers. We learned that measurements as small as the diameter of an atom or large as the distance to the Moon would take up too much space and be difficult to read without using scientific notation. Then we learned the steps to place a number in scientific notation.
1. Write the original number.
A. 149,600,000
B. 0.000000028
2. Move the decimal point to the right or the left to make the number greater than or equal to one and less than 10. Count the number of decimal places moved and note the direction.
A. 1.49600000 = 8 places to the left
B. 00000002.8 = 8 places to the right
3. Rewrite the number deleting all extra zeros to the right or to the left of the decimal point.
A. 1.496
B. 2.8
4. Write a multiplication symbol and the number 10 with an exponent. The exponent should equal the number of places that you move the decimal point in step two. If you moved the decimal point to the left, the exponent is positive. If you moved the decimal point to the right the exponent is negative.
A. 1.496 x 108
B. 2.8 x 10-8
• Diameter of an atom 0.0000000001 to 0.0000000005 in scientific notation 1 × 10-10m to 5 × 10-10m
• Distance to the moon 238,855 miles in scientific notation 2.38855 x 105miles