1. Aim: How to write in Scientific Notation and Count Significant Figures
Do Now:
What does 105 mean?
What is the value of 105.
Using your calculator, calculate 4.5 X (input as 4.5 X 10^6)
Would it easier to write the whole value or just as 4.5 X 106 Explain.

2. Scientific Notation
In scientific notation, a given number is written as the product of two numbers; a coefficient and 10 raised to a power.
Scientific notation is the way that scientists easily handle very large numbers or very small numbers. For example, instead of writing , we write 5.6 x 10-9

3. Examples
10000 = 1 x 104
24327 = x 104
1000 = 1 x 103
7354 = x 103
100 = 1 x 102
482 = 4.82 x 102
10 = 1 x 101
89 = 8.9 x 101 (not usually done)
1 = 100
1/10 = 0.1 = 1 x 10-1
0.32 = 3.2 x 10-1 (not usually done)
1/100 = 0.01 = 1 x 10-2
0.053 = 5.3 x 10-2
1/1000 = = 1 x 10-3
= 7.8 x 10-3
1/10000 = = 1 x 10-4
= 4.4 x 10-4

4. Writing in Scientific Notation
When expressing a whole number in scientific notation
If you move decimal to the right, the exponenet gets a negative number
If you move the decimal to the left, the exponenet gets a positive number
When writing in scientific notation
If you see a negative exponent, move the decomal that many times to the left
If you see a positive exponent, move the decimal that many times to the right

5. Practice Write out the whole number 1.3 X 105 1.3 X 10 -5
Write the following in scientific notation

6. Scientific Notation and Your Calculator
How to input scientific notation on your scientific calculator:
Us the ^ button before exponent
( 3.7 x 10 ^ 3)
When doing calculations with scientific notation, put your numbers in scientific notation in parenthesis
(2.3 x 104) – (3.7 x 103)
If a number like this shows up your calculator :
1.89E5 it is the same as 1.89 x 105

7. Your Turn (On your Own)
Question 1 Write in scientific notation: and
Question 2 Express 5.43 x 10-3 as a number not in scientific notation.
Question 3 (4.5 x 10-14) x (5.2 x 103) = ?
Question 4 (6.1 x 105)/(1.2 x 10-3) = ?

8. Significant Figures
Significant figures refers the digits in a measured number (or in the result of a calculation with measured numbers) that include all certain digits plus a final digit having some uncertainty.

9. Rules to Significant Figures
All non-zero digits (1, 2, 3, 4, etc.) are significant.
Zeroes between non-zero digits are significant. Ex: 101
Zeroes to the left of the first non-zero digit are not significant. Ex
Zeroes to the right of the last non-zero digit are significant if there is a decimal point present, but not significant if there is no decimal point.
Significant: 100. has three significant figures
Not significant: 100 has one significant figure

10. Significant Figures in Calculations
For addition and subtraction problems, the answer should be rounded off to the same number of decimal places as the measurement with the fewest decimal places.
184.2 grams grams = grams ≈ grams

11. Significant Figures in Calculations
For multiplication and division problems, round off the answer to the same number of significant figures in the measurement with the fewest significant figures.
100.0 grams of water x ( grams cisplatin/25.31 grams of water ) = ≈ grams