1. Scientific Notation & Significant Figures

2. Scientific Notation Why do we need it?
It makes it much easier to write extremely large or extremely small numbers.

3. Scientific Notation What would you rather write?
602,200,000,000,000,000,000,000 Or
6.02 x 1023

4. Scientific Notation
6.02 x 1023 Writing the number like this means you will take the number 6.02 and multiply it by 10 twenty three times

5. Scientific Notation
Every time the decimal moves left or right one place it is divided or multiplied by ten.

6. Scientific Notation
101 = = 1, = 100, = = =

7. Scientific Notation
1. Move the decimal so that there is only one non zero number in front of it
5,050,000,000

8. Scientific Notation
1. Move the decimal so that there is only one non zero number in front of it
5,050,000,000

9. Count how many places the decimal had to move
Scientific Notation
Move the decimal so that there is only one non zero number in front of it
Count how many places the decimal had to move 9

10. Scientific Notation
Move the decimal so that there is only one non zero number in front of it
Count how many places the decimal had to move
This number now becomes the exponent in the scientific notation. If the decimal moved to the left the exponent is positive, if it moved to the right the exponent is negative.
5.05 x 109

11. 5,050,000,000
Equals
5.05 x 109
They are the same number

12. Try a really small number 0.0000000122
Write this number in scientific notation.

13. Try a really small number
1.22

14. 0.00000001.22 8 1.22 x 10-8 Write this number as the exponent.
The decimal moved left how many spaces? 8
Write this number as the exponent.
1.22 x 10-8

15. Significant Figures

16. Sig Figs answer the question of “How many places should I round to
Sig Figs answer the question of “How many places should I round to?” or “How many decimals do I keep?”

17. Accuracy – how close a measurement is to the true value of the quantity measured
Precision – the exactness of a measurement

18. The number of sig figs you keep in an answer totally depends on the precision and accuracy of the instruments you are using.

19. Rules to find Sig Figs If the Number is not a zero it is significant
If zeros are in between two non zero numbers it is significant
Zeros before a non zero number are not significant.
Zeros after non zero numbers are significant only if there is a decimal.

20. 352
4505
1240
130.0

21. When Multiplying/Dividing keep the smallest number of sig figs in the answer.
When Adding/Subtracting keep the smallest number of decimals in the answer.