1. BELL WORK How many space do you move the decimal to make it whole number? 0.002 3 spaces How many spaces do you move the decimal to make it 4? 4000000 6 spaces

2. Section 8.4 Scientific Notation April 22, 2010

3. What Will We Learn Today? How to represent and interpret numbers using scientific notation

4. Take A Guess… Do you know this number, 300,000,000 m/sec.? It’s the speed of light! What is Avogadro’s number? 602,200,000,000,000,000,000,000,000 - 23 zeros!!

5. Scientists have developed a shorter method to express very large numbers. This method is called scientific notation. Scientific Notation is based on powers of the base number 10.

6. Scientific Notation 10 0 = 10 1 = 10 2 = 10 3 = 10 4 = 10 5 = Do you see a pattern?  exponent 2, two zeros  exponent 0, no zeros  exponent 1, one zero  exponent 3, three zeros  exponent 4, four zeros  exponent 5, five zeros 1 100 10 1000 10000 100000

7. Back to Avogadro’s number 602200000000000000000000000 How many zeros? How would you write it? What about the 6022? - becomes 6.022 x 10 23 10 23

8. The number 123,000,000,000 in scientific notation is written as… The first number 1.23 is called the coefficient. It must be greater than or equal to 1 and less than 10. The second number is called the base. It must always be 10 in scientific notation. The base number 10 is always written in exponent form. x 10 11 1.23

9. How to write a number in scientific notation: Begin with 123,000,000,000 –Put the decimal after the first digit and drop the zeroes. 1.23000000000 -Count and move decimal over to the left until last zero 1.23000000000 -Since the decimal can be moved over 11 spots to the left, the exponent is11 GOAL: _________ x 10 coefficient 1.23 ___ exponent 11

10. With your partner try these… 1). 8000 8 x 10 3 2). 65000000000 6.5 x 10 10 3) 14000000 14 x 10 7

11. What is this number? Do you recognize this number, 0.000000000753 kg. ? It’s the mass of a dust particle!

12. How to write a really small number in scientific notation Begin with 0.00000225 -Put the decimal after the first number other than zero (boxed area becomes coefficient) 0.000002.25 -Count how many spaces the decimal is moved to the right (this become a negative number which is the exponent) GOAL: _________ x 10 coefficient 2.25 ___ exponent -6

13. When to use a positive exponent POSITIVE EXPONENT –For very BIG, LARGE, HUGE, numbers such as… 1). World population 5 x 109 or 5,000,000,000 2). Seconds in a year 3 x 107 or 30,000,000 3). Average hairs on head 2 x 106 or 2,000,000

14. When to use a negative exponent NEGATIVE EXPONENT - For very SMALL, TINY, MICROSCOPIC numbers 1). Time taken by light to travel one meter 3 × 10 -9 (seconds) or 0.000000003 seconds 2). The charge on an electron 1.6 × 10 -19 C or 0.00000000000000000016 Celsius

15. With your partner try these… 1). 0.00000059 5.9 x 10 -7 2). 0.507 5.07 x 10 -1 3) 0.04 4 x 10 -2

16. Carousel Get with your group and work together to solve the questions at each station.

17. Journal Time Write in your own words when you would use a positive exponent and when you would use a negative exponent Explain how using scientific notation might be useful for you in real life

18. Homework In text: # 1- 21 odd, 34-52 even, 60-70 all All Due Tomorrow