1. 2-10 10/21 & 10/24/11 Scientific Notation
Ex 1. The sun is 93 million miles from the Earth, yet the next closest star is 270,000 times farther away. How far is the next closest star from Earth?

2. Scientific Notation – A number greater than 1, but less than 10 multiplied by a power of 10

3. Light year (lt-yr) – the distance traversed by light in one mean solar year. Approximately 5.88 trillion miles
(9.46 trillion km)
Ex 2. The sun is 30,000 light years from the center of our galaxy.
How many miles is the sun from the center of our galaxy?

4. Ex 3. Convert each to scientific notation.
Speed of Light:
300,000,000 m/sec
B) Mass of a dust particle: kg

5. Ex 4. Write in scientific notation.
48,000,000,000
Ex 5. Write in standard form.
6.04 x 104
9.7 x 10-4

6. Homework:
p. 132 #’s 2-24 even

7. 10/24/11 Do-Nows a. Write in scientific notation. 75,000,000
b. Write in standard form.
8.12 x 105
6.4 x 10-3

8. c. Write each in standard form and scientific notation.
50.2 million
1,567 million

9. Ex 6. Order the planets from smallest to largest.

10. Planet
Radius (km)
Earth
6.38 x 103
Jupiter
7.14 x 104
Mars
3.40 x 103
Mercury
2.44 x 103
Neptune
2.43 x 104
Saturn
6.0 x 104
Uranus
2.54 x 104
Venus
6.05 x 103

12. Evaluate and write your answer in both decimal and scientific form.
Ex 7. (6.2 x 102)(8 x 103)
4,960,000; 4.96 x 106
Ex 8. (3 x 105)(6 x 102)
180,000,000; 1.8 x 108

13. p #’s 2-32 even, 37, 38

14. HW: p. 132 #’s 9, 26-32, even 37,38