OBJECTIVE/WARM-UP

• Students will be able to distinguish between accuracy and precision.

• Students will be able to use scientific notation.

• How many sig figs in each number?• 3.400• 0.00304• 0.34090• 0.0030• 4500

NOTES-ACCURACY

Word/Phrase: Definition:

Hints or diagram: Meaning in My own words:

accuracy How close the measurement is to the real, true, orcorrect value

correctness

NOTES-PRECISION

Word/Phrase: Definition:

Hints or diagram: Meaning in My own words:

precision How close measurementsare to each other

repeatable

On the TV show “The Biggest Loser”, weight loss is reported in whole pounds, but percentage weight loss is given with two decimal places. For example, if a 210 lb. person lost 4 pounds, the percent weight loss is reported as 1.90% weight loss. Write a letter to the producers of the show to explain how this is unfair and not correct precision in reporting the percentage weight loss. Suggest a way to correct this for future shows.

Scientific Notation

A short-hand way of writinglarge numbers without writing all of the zeros.

The Distance From the Sun to the Earth

93,000,000

Large Numbers

Step 1

Move decimal left

Leave only one number in front of decimal

Step 2

Write number without zeros

Step 3

Count how many places you moved decimal

Make that your power of ten

The power often is 7 becausethe decimalmoved 7 places.

93,000,000 --- Standard Form

9.3 x 107 --- Scientific Notation

Practice Problem

1) 98,500,000 = 9.85 x 10?

2) 64,100,000,000 = 6.41 x 10?

3) 279,000,000 = 2.79 x 10?

4) 4,200,000 = 4.2 x 10?

Write in scientific notation. Decide the power of ten.

9.85 x 107

6.41 x 1010

2.79 x 108

4.2 x 106

More Practice Problems

1) 734,000,000 = ______ x 108

2) 870,000,000,000 = ______x 1011

3) 90,000,000,000 = _____ x 1010

On these, decide where the decimal will be moved.

1) 7.34 x 108 2) 8.7 x 1011 3) 9 x 1010

Complete Practice Problems

1) 50,000

2) 7,200,000

3) 802,000,000,000

Write in scientific notation.

1) 5 x 104 2) 7.2 x 106 3) 8.02 x 1011

Scientific Notation to Standard Form

Move the decimal to the right

3.4 x 105 in scientific notation

340,000 in standard form

3.40000 --- move the decimal

Write in Standard Form

6.27 x 106

9.01 x 104

6,270,000

90,100

Small Numbers

Step 1

Move decimal right

Leave only one number in front of decimal

Step 2

Write number without zeros

Step 3

Count how many places you moved decimal

Make that your power of ten

The power often is -4 becausethe decimalmoved 4 places.

0.000324 --- Standard Form

3.24 x 10-4 --- Scientific Notation

Practice Problem

1) 0.000000985 = 9.85 x 10?

2) 0.641 = 6.41 x 10?

3) 2.79 = 2.79 x 10?

4) 0.042 = 4.2 x 10?

Write in scientific notation. Decide the power of ten.

9.85 x 10-7

6.41 x 10-1

2.79 x 100

4.2 x 10-2

Complete Practice Problems

1) 0.005

2) 0.000072

3) 0.000802

Write in scientific notation.

1) 5 x 10-3 2) 7.2 x 10-5 3) 8.02 x 10-4

Scientific Notation to Standard Form

Move the decimal to the left

3.4 x 10-5 in scientific notation

0.000034 in standard form

000034 --- move the decimal

Write in Standard Form

6.27 x 10-6

9.01 x 10-4

0.00000627

0.000901

Scientific Notation ExamplesChange from scientific notationa) the distance from Pluto to the Sun is 5.9×10 12 metersb) the Milky Way disk radius is 3.9×1020 meters.c) The speed of light is 3 x 10 8 meters/second.d) the sun is 1.5x 1011 meters from earthe) Mass of proton : 1.6726 x 10-27 kgf) Mass of neutron: 1.6749 x 10-27 kgg) Mass of electron: 9.10939 × 10-31 kg Change into scientific notationh) 0.000 000 000 753 kg. is the mass of a dust particle! i) A proton has a diameter of approximately

0.000000000001 mm

Quick Review

When adding or subtracting:Make sure the exponents are the same

and line up the decimal points.

When multiplying:Add the exponents

When dividing:Subtract the exponents