Chapter 1: Introduction to
Science
1.1 The Nature of
Science
1.2 The Way
Science Works
1.3 Organizing
Data
Vocabulary
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Scientific Notation
Precision
Significant figures
Accuracy
Line Graphs
• Line Graphs: best for showing data that
changes continuously
• x-axis: independent variable (bottom of
graph)
• y-axis: dependent variable (side of graph)
Line Graph Examples
Bar Graphs
• Bar Graphs: useful
for comparing data
for several individual
items
• Makes large or
small differences
in data very clear
Bar Graph Examples
Pie Chart
• Pie Chart: useful for displaying data that
are parts of a whole
• Add up to 1 or 100%
Parts of a Graph
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Title of Graph
Label axis/pie chart
UNITS!
All data
Zero (on line and bar graphs)
Set up EQUAL divisions
Analyzing Data from Graphs
• Outliers: data that is abnormally high or
low
• Unusual or rare data
• Mean: the average (add up all data
points and divide by total number of
data points)
Analyzing Data from Graphs
• Median: number in the middle when
data is displayed from least to greatest
• Mode: the data that shows up the most
often
Significant Figures (aka “sig figs”)
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Rules for Sig Figs:
1. Non-zero digits are ALWAYS significant
2. Any zeros between sig figs ARE
significant
3. A final zero or trailing zero in the decimal
portion ONLY are significant
Sig Fig Examples
• How many sig figs are in each number?
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3.0800
0.00418
7.09 x 10-5
91,600
0.003005
3.200 x 109
250
780,000,000
0.0101
0.00800
Significant Figures in calculations:
• When you +, -, ×, or
÷, your answer
should only be as
precise as the least
precise
measurement in the
calculation
Sig Figs
• Example: A gummy bear has the
dimensions of 1.34 cm long, 0.82 cm
wide, and 1.0 cm high. Find the volume
of the gummy bear with the correct # of
sig figs. (Remember: V = l × w × h)
Scientific Notation
• Why? So scientists can easily express
numbers that are very large or very small.
• What? A simple number (1 or greater AND
less than 10) multiplied by a power of 10
• Examples:
• 6.24 × 106
• 2.1 × 10-2
Scientific Notation
•
How?
1. Using original number, move decimal so
that the number is one or greater and
less than 10.
2. Count how many places the decimal was
moved.
Scientific Notation
• If the number you started with is greater
than 1, the exponent is POSITIVE
• If the number you started with is less
than 1, the exponent is NEGATIVE
• Scientific notation can be reversed to
write the number in standard form
again.
Accuracy vs. Precision
• Accuracy: how close a measurement is
to the true value
• Precision: how exact a measurement is
Low Accuracy
High Precision
High Accuracy
Low Precision
High Accuracy
High Precision