Wednesday, 08/30/2016 Scientific Notation

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!)

Objective The 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.

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? 23 When 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? 9.02 The decimal was moved how many places? 8 When the original number is less than 1, the exponent is negative. 9.02 x 10-8

Write 28750.9 in scientific notation. 2.87509 x 10-5 2.87509 x 10-4 2.87509 x 104 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 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.

Objective The student will be able to: Correctly compute numbers in scientific and decimal notation. Designed by Skip Tyler, Varina High School

To multiply numbers: Multiply the base numbers normally Add the exponents together. Example: 4.0 x 103 x 2.3 x 1010

To multiply numbers: Multiply the base numbers normally Add the exponents together. Example: 4.0 x 103 x 2.3 x 1010 Answer: 9.2 x 1013

To multiply numbers: Multiply the base numbers normally Add the exponents together. You try: 3.5 x 1020 x 5.7 x 1012

To multiply numbers: Multiply the base numbers normally Add the exponents together. You try: 3.5 x 1020 x 5.7 x 1012 Answer: 19.95 x 1032

To multiply numbers: Multiply the base numbers normally Add the exponents together. You try: 3.5 x 1020 x 5.7 x 1012 Answer: 19.95 x 1032 But this is NOT correct scientific notation and so we must change it to 1.995 x 1033

To divide numbers: Divide the base numbers normally Subtract the exponents. Example: 7.0 x 103 / 3.5 x 1010

To divide numbers: Divide the base numbers normally Subtract the exponents. Example: 7.0 x 103 / 3.5 x 1010 Answer: 2.0 x 10-7

To divide numbers: Divide the base numbers normally Subtract the exponents. You try: 72.6 x 1012 / 12.5 x 108

To divide numbers: Divide the base numbers normally Subtract the exponents. You try: 72.6 x 1012 / 12.5 x 108 Answer: 5.808 x 104

Guess how we will add/subtract That’s right—we need a common exponent, so we manipulate the notation to get one! Example: 1.00 x 103 + 1.00 x 102 A good rule to follow is to express all numbers in the problem in the highest power of ten. Convert 1.00 x 102 to 0.10 x 103, then add: 1.00 x 103 + 0.10 x 103 1.10 x 103

Add/Subtract Try Two You try now: Example: (4.56 x 106) + (2.98 x 105) + (3.65 x 104) + (7.21 x 103)

Add/Subtract Try Two You try now:

Finish the Worksheet: If you need help ask, I’ll be walking around the room.

Scientific Notation and other Chem Maths Thursday, 09/1/2016 Scientific Notation and other Chem Maths

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

Chem-o-loon 2 Teams (Boys v Girls…or…) 1 Balloons per person/ side 30 seconds to solve problems Select different people to compete If everyone gets the answer correctly on the winner’s team: two options (steal a balloon or earn one point) Keep writing on your balloon until you win—then pop it!

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: 3100:_______ 24.000:_________ .2500:_________ 2010:_______ 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