to students that you would like to know what eye colors are represented
in the class. Give each child an index card and crayons. Ask the
students to find a partner and write the color of their partner's eyes
on the index card. Encourage them to write as large as possible, using
a crayon color that matches the color of the student's eyes. Then ask
the students to give their partner the card that shows his or her eye
Now gather the students around you and ask them to display their
index cards. Invite them to make a tally mark (only one Tally Chart
will be used to record data from each of the students in the class) on
the chart paper. A sample tally chart is shown:
The Color of Our Eyes
Tell the students to line up if the color of their eyes is blue.
Then call out other eye colors and have the students line up in
parallel columns until all the class members have lined up and formed a
human bar graph.
Next, ask the first one in each row to collect the cards from that
group and tape them on the board to form a bar graph. Solicit a name
for the graph from the students. Ask the students to take their seats
and give each Graph Paper.
Instruct them to fill in the bars with the color of crayon that matches
the eye color displayed in that bar of the graph. You may wish to move
around the room to be sure that all students can complete a bar graph
from the data.
Ask the students what they can tell about the eye colors in the
class from looking at the bar graph. After the students give several
statements, encourage them to use numbers to describe the graph. You
might begin by asking questions about the number of students with a
certain eye color. The next set of questions might compare two bars on
the graph. Lead the students to notice, which color was most frequently
represented and which were least represented. Inform them that the
difference between these numbers is called the range. Ask them to
subtract to find the difference between the greatest number and the
least number in their set of data.
Next, inform them that the number found most often in a set of data
is called the mode. Ask them to identify the mode in this set of data.
Using the NCTM Bar Grapher tool, create a bar graph of the class data.
Call on students to choose a name for the bar graph and the colors of the bars.
Ask students how the computer-generated graph is similar to the bar graphs they created on graph paper.