Unit 2:
Measurem
ent & Data8th Grade
Mrs. Morgan
Review: Once AgainData- the facts, figures, and other evidence scientists gather when they conduct an investigation.
Independent variable- (x axis) the variable that is deliberately manipulated (changed on purpose)
Dependent variable-(y axis) changes value as others change.
3 Types of Graphs 1. line graph shows relationship where
the dependent variable changes b/c of the independent variable
• Scatter plot
http://4.bp.blogspot.com/_46URaoUSp0A/S9B6OMq9qfI/AAAAAAAAAGE/IcQA37CwMT4/s1600/scatterplot.gif
2. Bar graph
compare information collected by counting.
3. Circle or Pie graph show how a whole is broken into parts.
Reading Graphs• Linear relationship-the relationship
between the independent and dependent variable can be shown with a straight line.
• Nonlinear relationship-any relationship between the variables that cannot be shown with a straight line.
Direct relationship-upward sloping line
Inverse relationship-downward sloping line
Model-representation of an object or a process that allows scientist to study something in greater detail.
Measurement- description that includes a number and unit
SI- improved version of the metric system used worldwide.
Based on multiples of 10.
Base Units
1.Length (m)-distance between 2 points
2.Mass (kg)-how much matter is in an object
3.Time (s)-interval between 2 events
4.Temperature (K or ˚C)- how hot or how cold something is
5.Volume (L, or cm3)-amount of space occupied by an object
Derived unit -combining different SI units Density -mass per unit volume of a material OR simply how packed together something is.
The unit is g/cm3 for example: g=grams and cm3 =volume
kilo-
hecto-
deka-
deci-
centi-
milli-
0.1 =
0.01 =
0.001 =
m
meter
cm
centi-
dm
deci-
mm
milli-
dkm
deka-
hm
hecto
km
kilo-
54 hm = ? cm
54
1. Copy the #2. Find Dewey
m
cm
dm
mm
dkm
hm
km
54 hm = ? cm
3. Move Dewey
0 0 0 0 cmx
540,000 cm
54 hm = ? cm
1 dm = ? m
1
1. Copy the #2. Find Dewey
m
cm
dm
mm
dkm
hm
km
1 dm = ? m
3. Move Dewey
m
x
.1 m
1 dm = ? m
Measurements must have a # & a unit.
.1 m
1 dm = ? m
0
Scientific Notation-short way of representing very large or very small numbers
Accuracy-description of how close a measurement is to the true value of the quantity measured.
Precision-the
exactness of a
measurement.