GRAPHING
• Using the following data we will look at how to assemble a
line graph to represent the relationship between number
of wraps of wire and number of paper clips picked up.
Trial
Number
One
Two
Number wraps
of wire
8
15
Number of paper
clips picked up
6
14
Three
28
19
Our graph will be made on a grid that is
10 X 10, but any grid would work.
The vertical
axis
is called
the
“Y” axis.
The horizontal axis is called the “X” axis.
The independent variable is the
data that we control.
For example . . .
The student determines how many wraps of
wire they will use.
So, the number of wraps of wire is the
independent variable.
We will plot the independent variable on the
horizontal (X axis).
Label this axis
Number of wraps of wire
Number of paper clips picked up
The dependent variable is the data that
depends on what the students does.
The student determines how many wraps of
wire they will use but, they don’t know how
many paper clips the magnet will pickup.
So, the number of paper clips picked up is
the dependent variable.
We will plot the dependent variable on the
vertical (Y axis).
Label this axis
Number of wraps of wire
Number of paper clips picked up
Electromagnet Strength:
Wraps vs. Number of Paper Clips
Place an informative title at the top.
Number of wraps of wire
Number of paper clips picked up
Electromagnet Strength:
Wraps vs. Number of Paper Clips
Now we are ready to number the graph.
Number of wraps of wire
First, let’s go back and look at the data.
Trial Number
Numberofwraps
Number
wrapsofofwire
wire
Number of paper clips picked up
One
8
6
Two
15
14
Three
28
19
We’ll begin with the independent variable, the number of wraps of wire.
The largest number we have is 28,
For the smallest number we will use 0.
If we had 0 number of wraps the magnet would pick up 0 paper clips.
So the range of numbers on the
horizontal (X axis) must go from 0 to at least 28.
Number of paper clips picked up
Numbers should line up with the
vertical lines . . .
not between lines.
0
1
Number of wraps of wire
How do we get numbers from 0 to 28 to fit
on a grid that only has 10 lines?
Number of paper clips picked up
The lines can be any value we decide
as long as we stay consistent on an axis.
We could number our horizontal (X axis)
by 1’s, but that would only get us up to 10.
We need to go to 28.
0
1
2
3
4
5
6
7
Number of wraps of wire
8
9
10
Number of paper clips picked up
Numbering by 2’s will only take us to 20.
We do not need to end at exactly 28, and if
we number by 3’s we can take any number
up to 30.
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30
20
Now we do the same thing with the
vertical (Y axis).
Number of paper clips picked up
18
16
This axis does not need to have the same
numbering as the X axis.
14
For this axis we need a range that goes
from 0 to at least 19.
12
If we number this axis by 2’s we can get
all the way to 20.
10
8
6
4
2
0
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30
Electromagnet Strength:
Wraps vs. Number of Paper Clips
20
Number of paper clips picked up
18
16
14
12
Now we can plot the actual data.
10
8
6
4
2
0
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30
Trial
Number
Number wraps of
20
wire
One
One
Three
Number of paper clips picked up
Two
Number of paper clips
picked up
The first point will be for trial 1.
66
88
18
15
14
28
19
16
14
12
Locate 6 on the Y axis.
10
Locate where 8 can be found on the X
axis. It is between 6 and 9, closer to 9.
Plot a point on the graph where
these two lines intersect.
8
6
4
2
0
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30
Plot the points for trials 2 and 3.
20
Number of paper clips picked up
18
16
14
Trial
Number
Number wraps of
wire 12
Number of paper clips
picked up
One
8
6
Two
Three
15
28
10
14
19
8
6
4
2
0
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30
20
Number of paper clips picked up
18
16
14
12
10
8
We can plot a final point at 0 on the X
axis and 0 on the Y axis since zero
wraps will not pick up any paper clips.
6
4
2
0
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30
Electromagnet Strength:
Wraps vs. Number of Paper Clips
20
Number of paper clips picked up
18
16
14
12
10
8
6
4
Finally, connect the points with a line.
2
0
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30
Electromagnet Strength:
Wraps vs. Number of Paper Clips
20
Number of paper clips picked up
18
16
14
12
10
8
6
4
2
0
Nice!
0
3
6
9
12
15
18
21
Number of wraps of wire
24
27
30