1. Significant Figures and Scientific Notation
Making Sense of BIG Numbers

2. What should an eagle be able to do?
Accurately count the total number of significant digits
Convert Scientific Notation to Numbers
Convert Numbers to Scientific Notation
Use Scientific Notation Mathematical rules for: Adding & Subtracting
Dividing and Multiplying

3. Significant Numbers Rules made simple
Numbers 1 – 9 are always significant.
Zero Rules:
Leading zeros
Trailing zeros with decimal
Trailing zeros without decimal
Captive zeros

4. How to Convert Numbers to Scientific Notation
If a number is greater than one, its exponent should be positive.
Locate the original decimal place and move the decimal to the
left until you get the right side of the 1st sig fig.
For example: > x 102
2. If a number is less than one, Its exponent should be negative.
right until you get the right side of the 1st sig fig.
For example: > x 10-3

5. How to convert scientific notation to numbers
If the exponent is positive, it means that the original number was greater than one. Move the decimal to the right
For example: x  230
If the exponent is negative, it means that the original number
was less than one. Move the decimal to the left
For example: x 

6. Mathematical rules for scientific notation
Addition and subtraction
(decimal places)
FOR EXAMPLE
Count the # of decimal places to determine the number of significant figures.
The answer cannot contain more places after the decimal point than the smallest number of decimal places in the numbers being added or subtracted.
(6 places after decimal)
( 4 places after decimal)
+ 0.25_ ( 2 places after decimal)
Since 0.25 has the least # of decimal places, your answer should have 2 places after the decimal point
On calculator you get 
Your final answer should be  24.69

7. Mathematical rules for scientific notation
Multiplication and division (Sig FiGs)
For Example
Count the # of significant figures.
The answer cannot contain more significant figures than the number being multiplied or divided with the least number of significant figures.
(8 sig figs)
X (5 sig figs)
Since has the least # of sig figs then your answer should have 5 sig figs
On your calculator you get:
Your final answer should be:

8. It’s now Time to practice!
PowerPoint Courtesy of Ms. Christal Owens WHS Chemistry Team