DIFFERENTIATE: ACCURACY AND PRECISION Three targets with three arrows each to shoot. Can you hit the bull's-eye? Both accurate and precise Precise but.

Slides:



Advertisements
Similar presentations
Significant Figures All IB calculations must report answer to correct # of sig fig’s. All lab measurements must be reported to correct sig fig’s and correct.
Advertisements

1 1.8 Significant Figures Chapter 1 Matter, Measurements, & Calculations Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings.
“A man with a watch knows what time it is. A man with two watches is never sure” (Unknown)
Chapter 2 Measurements Measured Numbers and Significant Figures.
UNIT ONE TOPIC: Significant Figures and Calculations.
Significant Figures.
SCIENTIFIC MEASUREMENT  CHEM IH: CHAPTER 3. What is Scientific Notation?  Scientific notation is a way of expressing really big numbers or really small.
NOTES – SIGNIFICANT FIGURES (SIG FIGS) ANY DIGIT OF MEASUREMENT KNOWN WITH CERTAINTY PLUS ONE FINAL DIGIT WHICH IS ESTIMATED.
Significant Figures Significant figures in a measurement includes all of the digits that are known, plus a last digit that is estimated. All measurements.
Using and Expressing Measurements
Significant Figures.
A measured value Number and unit Example 6 ft.. Accuracy How close you measure or hit a true value or target.
Significant Figures Physical Science. What is a significant figure? There are 2 kinds of numbers: –Exact: the amount of money in your account. Known with.
Significant Figures. What is a significant figure? There are 2 kinds of numbers: 1. Exact : Known with certainty. Example: the number of students in this.
Chapter 1 Lesson4. Physical Science  There are 2 kinds of numbers: ◦ Exact: the amount of money in your account. Known with certainty.
Significant Figures Chemistry. Exact vs approximate There are 2 kinds of numbers: 1.Exact: the amount of money in your account. Known with certainty.
 There are 2 kinds of numbers:  Exact: the amount of money in your account. Known with certainty.  Approximate: weight, height— anything MEASURED.
Scientific Notation & Significant Figures Scientific Notation  Scientific Notation (also called Standard Form) is a special way of writing numbers that.
MEASUREMENTS. What is the difference between these two measurement rulers? Should we record the same number for each scale reading? The second scale gives.
ACCURACY AND PRECISION ACCURACY: refers to how close a measured value is to an accepted value PRECISION: refers to how close a series of measurements.
Motion Unit Measurements Significant Figures in Calculations.
Significant Figures. What is a significant figure? There are 2 kinds of numbers: –Exact: the amount of money in your account. Known with certainty.
Significant Figures. What is a significant figure? The precision of measurements are indicated based on the number of digits reported. Significant figures.
Significant Figures Physical Science. What is a significant figure? There are 2 kinds of numbers: –Exact: counting objects, or definitions. –Approximate:
DIFFERENTIATE: ACCURACY AND PRECISION Three targets with three arrows each to shoot. Can you hit the bull's-eye? Both accurate and precise Precise but.
Significant Figures SPH3U. Precision: How well a group of measurements made of the same object, under the same conditions, actually agree with one another.
Significant Figures In Measurements. Significant Figures At the conclusion of our time together, you should be able to: 1. Explain what significant figures.
1 INTRODUCTION IV. Significant Figures. A. Purpose of Sig Figs Units of Measurement: Measurements indicate the magnitude of something Must include: –A.
Welcome to the World of Chemistry Measurement, Scientific Notation, Significant Figures.
Significant Figures… Bluefield High School 1. What is a significant digit? Significant digits is a set of internationally accepted rules for measurement.
Significant Figures and Scientific Notation. What is a Significant Figure? There are 2 kinds of numbers:  Exact: the amount of money in your account.
1 Significant Figures (Sig Figs) Quantity includes all known digits plus one estimated digit = last digit of # Indicates precision 500 vs
Bell Ringer: Oct. 4, 2010: Complete the table below. Place X in the appropriate box to indicate the type of each measurement unit. Reference: Physical.
WHAT WE HAVE LEARNED. SCIENTIFIC NOTATION 1. Move the decimal to the right of the first non-zero number. 2. Count how many places the decimal had to.
Significant Figures Chemistry I. Significant Figures The numbers reported in a measurement are limited by the measuring tool Significant figures in a.
Chapter 3.1 Accuracy and Precision Significant Figures.
Welcome to the World of Chemistry Part II Metric Prefixes.
Significant Figures. What is a significant figure?  There are 2 kinds of numbers:  Exact: the amount of money in your account. Known with certainty.
Bellringer: Write down the 3 Quick Rules for Sig Fig zeros:
Significant Figures Measure the length of your hand in cm.
Significant Figures Physical Science.
Significant Figures & Percent Error Calculation
Significant Figures Sig Figs.
Significant Figures in Calculations
BELLWORK 9/13/16 1 Tm = 1012 m 1mm = 10-3 m 1Mm = 106 m
What is a significant figure?
Significant Figures in Calculations
Unit-1 Physics Physical World and Measurements
Lab Safety List 3 unsafe lab activities you see in the picture.
Significant Numbers in Calculations
Lab Safety List 3 unsafe lab activities you see in the picture.
Significant Figures Physical Science Mr. Ramirez.
Unit 2- Measurements- Significant Figures & Scientific Notation
Accuracy and Precision
Significant Figures Physical Science.
BELLWORK 9/01/17 Complete #’s 1, 12, 22, and 34 in the new Virginia Bellwork Packet.
SI Units The worldwide scientific community and most countries currently use an adaptation of the metric system to state measurements. The Système International.
Significant Figures Chemistry.
Significant Figures.
Significant Figures.
Accuracy and Precision
BELLWORK 9/2/15 How does a scientist reduce the frequency of human error and minimize a lack of accuracy? A. Take repeated measurements B. Use the same.
Significant Figures in Calculations
Significant Figures.
Accuracy, Precision, & Significant Figures
How do you determine where to round off your answers?
The Mathematics of Chemistry
Significant Figures Physical Science.
Significant Figures in Calculations
Significant Figures.
Presentation transcript:

DIFFERENTIATE: ACCURACY AND PRECISION

Three targets with three arrows each to shoot. Can you hit the bull's-eye? Both accurate and precise Precise but not accurate Neither accurate nor precise How do they compare? Can you define accuracy and precision? What would a bullseye with accuracy and no precision look like?

Significant Figures

What is a significant figure? There are 2 kinds of numbers: –EXACT: the amount of money in your account, jelly beans in a jar, etc.. Known with certainty –APPROXIMATE (OR MEASURED): weight, height—anything MEASURED….USE SIG FIGS!  No measurement is perfect.

Reading a Meterstick. l I.... I 3....I.... I 4.. cm First digit (known)= 2 2.?? cm Second digit (known)= ? cm Third digit (estimated) between Length reported=2.75 cm or2.74 cm or2.74 cm or2.76 cm

Known + Estimated Digits In 2.76 cm… Known digitsandare 100% certain Known digits 2 and 7 are 100% certain The third digit 6 is estimated (uncertain) The third digit 6 is estimated (uncertain) In the reported length, all three digits (2.76 cm) are significant including the estimated one In the reported length, all three digits (2.76 cm) are significant including the estimated one

When to use Significant figures To a mathematician 21.70, or is the same. But, to a scientist 21.7cm and 21.70cm is NOT the same

When to use Significant figures When a measurement is recorded only those digits that are dependable are written down.

Always estimate ONE place past the smallest mark!

Zero as a Measured Number. l I.... I I.... I 5.. cm What is the length of the line? First digit 5.?? cm Second digit 5.0? cm Last (estimated) digit is 5.00 cm

Enter question text.... l I.... I 9....I.... I 10.. cm What is the length of the line? 1) 9.6 cm 2) 9.62 cm 3) 9.63 cm 3) 9.63 cm How does your answer compare with your neighbor’s answer? Why or why not?

Significant Figures The numbers reported in a measurement are limited by the measuring tool The numbers reported in a measurement are limited by the measuring tool Significant figures in a measurement include the known digits plus one estimated digit Significant figures in a measurement include the known digits plus one estimated digit

Counting Significant Figures RULE 1. All non-zero digits in a measured number are significant. Only a zero could indicate that rounding occurred. Number of Significant Figures cm4 5.6 m kg___ m m___

How many sig figs in 65.8 kg

How many sig figs in m

Leading Zeros RULE 2. Leading zeros in decimal numbers are NOT significant. Number of Significant Figures mm mg kg____ mL mL ____

kg How many sig figs in kg

mL How many sig figs in mL

Sandwiched Zeros RULE 3. Zeros between nonzero numbers are significant. (They can not be rounded unless they are on an end of a number.) Number of Significant Figures 50.8 mm min kg____ m m ____

0.702 kg How many sig figs in kg

m How many sig figs in m

Trailing Zeros RULE 4. Trailing zeros in numbers without decimals are NOT significant. They are only serving as place holders. Number of Significant Figures 25,000 cm 2 25,000 cm yr yr3 48,600 L____ 48,600 L____ 25,005,000 g ____

48,600 L How many sig figs in 48,600 L

48,600. L How many sig figs in 48,600. L

25,005,000 g How many sig figs in 25,005,000 g

Which answers contain 3 significant figures? 1.) ) ) 4760

All the zeros are significant in , x 10 3

534,675 rounded to 3 significant figures is 534,675 rounded to 3 significant figures is , x 10 5

In which set(s) do both numbers contain the same number of significant figures? and and and 150,000

Significant Numbers in Calculations A calculated answer cannot be more precise than the measuring tool. A calculated answer cannot be more precise than the measuring tool. A calculated answer must match the least precise measurement. A calculated answer must match the least precise measurement. Significant figures are needed for final answers from Significant figures are needed for final answers from 1) adding or subtracting 1) adding or subtracting 2) multiplying or dividing

Adding and Subtracting The answer has the same number of decimal places as the measurement with the fewest decimal places one decimal place two decimal places answer 26.5 one decimal place

Learning Check In each calculation, round the answer to the correct number of significant figures. A = 1) ) ) 257 B = 1) ) ) 40.7

Multiplying and Dividing Round (or add zeros) to the calculated answer until you have the same number of significant figures as the measurement with the fewest significant figures.

Learning Check A X 4.2 = 1) 9 2) 9.2 3) B ÷ 0.07 = 1) ) 62 3) 60 C X = X ) 11.32) 11 3) 0.041

State the number of significant figures in each of the following: A m B L C g D m E. 2,080,000 bees Learning Check

How many sig figs? x ,000,

How many sig figs here? ,083,000,

How many sig figs here? ,000,050,

Sig Figs?? 640 a)1 b)2 c)3 d)4 e)5 f)6

Sig Figs?? a)1 b)2 c)3 d)4 e)5 f)6

Sig Figs?? a)1 b)2 c)3 d)4 e)5 f)6

Sig Figs?? a)1 b)2 c)3 d)4 e)5 f)6

Sig Figs?? 10,000 a)1 b)2 c)3 d)4 e)5 f)6

How many sig figs?

How many sig figs here? 1.02 x x x x x x10 5 x

How many sig figs here? 23 x 2 x x 21 x x x x

Metric Prefixes