GRAPHING
A picture is
worth a
thousand words!
Learning Target
• Use the variables of an experiment to
draw and label a graph.
What does a GOOD graph have?
A good graph has a TITLE that tells us
what we’re looking at…
EXAMPLES:
Height vs. foot length
Weight vs. amount of food
Time vs. number of deer
A good graph has a LABELED X-axis and Y-axis
with units…
Growth (inches)
Weight (grams)
Y-axis (vertical)…DEPENDENT VARIABLE!
Volume (liters)
Age (years)
X-axis (horizontal)…INDEPENDENT VARIABLE!
Intervals & Scaling
It is important to make sure that the intervals
on the X and Y axis are always equal.
•
•
•
•
1, 2, 3, 4, 5…
2, 4, 6, 8, 10…
5, 10, 15, 20…
10, 20, 30, 40…
Always use an interval that uses up the entire
graph. Spread it out and make it look pretty!
A good graph has correctly placed POINTS…
• Check your numbers to make sure they’re in the
right place!
A good graph has a BEST FIT LINE (if possible)…
• The line is a summary of
what’s happening in the
graph.
• It can be straight OR curved.
• It does NOT have to touch
every point on the graph!
This best fit line
is straight…
More best fit lines…
Remember, we are looking for a pattern!
This best fit line
is curved…
No best fit line for this
graph…there is no
pattern!
THE “PERFECT” GRAPH…
Money Earned (dollars)
Time vs. Money Earned
Time (hours)
Title, labeled axes, correct points AND a best fit line!
Bar Graphs
Mass, Length, and Width by Day
Measurement in g and cm
5
4,5
4
3,5
3
2,5
Mass
Length
Width
2
1,5
1
0,5
0
Day 1
Day 2
Mass, Length, and Width
Pie Charts
Class Grades by Percent
10%
20%
As
Bs
Cs
30%
Ds
40%
Interpreting Graphs
• It is VERY important that you are able to
interpret information from a graph.
• This skill will never go away!
• Let’s practice…
Identify the graph that matches
the following story.
I had just left home when I realized I had forgotten
my books so I went back to get them.
Identify the graph that matches
the following story.
Things were going fine until I had a flat tire.
Identify the graph that matches
the following story.
I started out calmly, but sped up when I realized I
was going to be late.
What kind of story would
describe the last graph?
• What percent of the day is
spent watching TV?
• How many hours are spent
sleeping?
• What activity takes up the
least amount of time?
• What activity takes up a
quarter of the day?
• What two activities take up
50% of the day?
• What two activities take up
25% of the day
Vocabulary
• Independent Variable
• Dependent Variable