1. 1.7 Scientific Notation and Significant Figures

2. Fun with Numbers! Everyone write this down!
Mass of the Sun
1,988, kg
Mass of an Electron

3. Scientific Notation: In science, we deal with some very LARGE numbers:
1 mole =
In science, we deal with some very SMALL numbers:
Mass of an electron = kg

4. Imagine the difficulty of calculating the mass of 1 mole of electrons!kg x
???????????????????????????????????

5. M x 10n Scientific Notation:
A method of representing very large or very small numbers in the form:
M x 10n
M is a number between 1 and 10
n is an integer
300,000,000 = 3.0 x 108
= 3.4 x 10-5

6. Scientific Notation Rules
Only one number should be to the left of the decimal
This is wrong: x 10-4
This is wrong: x 10-4
This is correct: 7.2 x 10-4
If the number goes down, the exponent goes up
If the number goes up, the exponent goes down

7. . 9 8 7 6 5 4 3 2 1
Step #1: Insert an understood decimal point
Step #2: Decide where the decimal must end up so that one number is to its left
Step #3: Count how many places you bounce the decimal point (This is equal to n)
Step #4: Re-write in the form M x 10n

8. 2.5 x 109
The exponent is the number of places we moved the decimal.

9. 1 2 3 4 5
Step #1: Insert an understood decimal point (Decimal point is given in this problem)
Step #2: Decide where the decimal must end up so that one number is to its left
Step #3: Count how many places you bounce the decimal point
Step #4: Re-write in the form M x 10n

10. 5.79 x 10-5
The exponent is negative because the number we started with was less than 1.

11. Example: The Distance From the Sun to the Earth is 93,000,000 miles
Step #1: 93,000,000.
Step #2: 93,000,000 =
Write numbers without zeros: = 9.3
Step 3: Count how many places you moved your decimal and make that your power of ten. (7 places)
Step 4: 9.3 X 107

12. Example 93,000,000 - Decimal or Standard Form
The Distance From the Sun to the Earth is 93,000,000 miles
93,000, Decimal or Standard Form
9.3 X Scientific Notion

13. Practice Problems: 98,500,000 = 9.85 x 10? 64,100,000,000 = 6.41 x 10?

14. Scientific Notation to Standard Form
Move the decimal to the right - The number to the power of 10.
Example:
3.4 x 105 in scientific notation
3.4 = (Move the decimal right five places)
340,000 in standard form

15. Practice Problems: 6.27 x 106 9.01 x 104 4.56 x 10-3 .00456 6,270,000
90,100
.00456

16. Significant Figures
The measurable units of a measuring device plus one estimated digit.

18. Significant Figures
.Left Right

19. Practice Problems
34.007
.0078
234000
1.005

20. Pie Graph and Table
A pie chart is a circular chart divided into sectors, each sector shows the relative size of each value.

21. Bar Graphs
A bar graph is a graph drawn using rectangular bars to show how large each value is. (The bars can be horizontal or vertical)

22. Line Graphs
A line graph is a graph that uses points connected by lines to show how something changes in value (as time goes by, or as something else happens).