Do Now:

• Given that there are 1,000,000 microseconds in a second. How many pennies would you have if you earned one for every microsecond you were in class today (43 minutes)?

• What is a shortcut that scientists might use to show REALLY big numbers?

Homework:

• All of the worksheet (NOT the addition/subtraction scientific notation) problems must be completed by tomorrow! (Thursday!)

ObjectiveThe student will be able to:

express numbers in scientific and decimal notation.

Designed by Skip Tyler, Varina High School

How wide is our universe?210,000,000,000,000,000,000,000 miles

(22 zeros)

This number is written in decimal notation. When numbers get this large,

it is easier to write them in scientific notation.

Scientific Notation

A number is expressed in scientific notation when it is in the form

a x 10n

where a is between 1 and 10

and n is an integer

Write the width of the universe in scientific notation.

210,000,000,000,000,000,000,000 miles

Where is the decimal point now?

After the last zero.

Where would you put the decimal to make this number be between 1 and 10?

Between the 2 and the 1

2.10,000,000,000,000,000,000,000.

How many decimal places did you move the decimal?

23When the original number is more than 1,

the exponent is positive.The answer in scientific notation is

2.1 x 1023

So let’s try:

• Estimate how small an atom is and let’s see how close you come to its true size:

http://learn.genetics.utah.edu/content/cells/scale/

So if we write its size in scientific notation in relation to the meter it would be:

Did You Know…

•What does the sun weigh?4,400,000,000,000,000,000,000,000,000,000 lbs.

•How much hydrogen does the sun burn each second?

•600,000,000 metric tons

1) Express 0.0000000902 in scientific notation.

Where would the decimal go to make the number be between 1 and 10?

9.02The decimal was moved how many places?

8When the original number is less than 1, the

exponent is negative.9.02 x 10-8

Write 28750.9 in scientific notation.

1. 2.87509 x 10-5

2. 2.87509 x 10-4

3. 2.87509 x 104

4. 2.87509 x 105

2) Express 1.8 x 10-4 in decimal notation.0.00018

3) Express 4.58 x 106 in decimal notation.

4,580,000

Write in PROPER scientific notation.(Notice the number is not between 1 and 10)

8) 234.6 x 109

2.346 x 1011

9) 0.0642 x 104

6.42 x 10 2

Write 531.42 x 105 in scientific notation.

1. .53142 x 102

2. 5.3142 x 103

3. 53.142 x 104

4. 531.42 x 105

5. 53.142 x 106

6. 5.3142 x 107

7. .53142 x 108

Chem-o-loon

• 2 Teams (Boys v Girls)

• 10 Balloons per side

• 30 seconds to solve problems

• First team to pop all balloons wins

• If everyone gets the answer correctly on the winner’s team: two options (steal a balloon or earn one point)

CHEM Order:

• Metric Conversions

• Sig Figs (E)

• Sig Figs (H)

• Scientific Notation

• Dimensional Analysis

CHEM: Metric Conversion

• 3000g:_________cg

• 2500mm:________km

• 3.4kL:________mL

• 5274.2sec:________hours

Sig Figs (E)

• DO ALL:1. 3100:_______

2. 24.000:_________

3. .2500:_________

4. 2010:_______

5. 0.98400:_______

Sig Figs (H)

• 2.4 + 31.72 + 7 =

• 735 x 10 =

• 24.7 – 17.35 – 2.325 =

• 1484 x 2.5 / 53.0 =

Scientific Notation (E)

• 3 002 000

• 24.7

• 2.97 x 104

• 0.000130 000

• 7.25 x 10-11

• 99.2 x 102

Dimensional Analysis:

• 23.5 pizzas:__________slices

• 13.25 eggs:___________dozens

• 25 km:_________miles

• 16.25yrs:_________days

• 26.229 km/hr:________m/s

And the Winner Is…..

Complete Exit Ticket:

• 2.77 x 1011

• 31 020 000

• 1.992 x 10-8

• 0.000000002

Do Now:

• Answer each question below:– How many sig figs?

2300_____ 1.420 x 10^3________

0.003_____ 304,000________

– Use scientific/decimal notation:3.0 x 10^4______ 7894.2________

40000000_______ 0.000004720_______

– Convert between units:500 mL = ____L 2423mg = ________kg

0.00003 km = ________mm

Homework:

• Complete Review sheet, if desired

• Be ready for small quiz tomorrow!

• Bring Pennies (between 5 and 10 per person would be good!)

Today:

• Foldable Creation– Rule Cheat Sheet for Chem Math– Watch the demo, but you fill in any information

you need—this should be rules and examples to help you jog your memory!

IP Work Time

• Practice with the Review Sheet

• If you need help, raise your hand and I will come to assist you.

Closing:

• What will you focus on in preparation for your quiz tomorrow?