the students to name the different colors of hair they have seen in the
school. Then have the students write their hair color on an index card
and form groups according to their hair color. (Creating a human graph,
as done in the previous lesson on eye color, can help the students with
various learning styles to make essential connections.) Display a blank
horizontal bar graph on the board, and select students to title the
graph and to fill in the row names with hair colors represented in the
The Color of Our Hair
Ask one student from each group to tell how many are in his or
her group. Then ask for a volunteer to color in bars representing the
number of students in his or her hair-color group and label the row
with the appropriate number. When the bar graph is completed, call out
two hair colors and ask which has the longer bar. Ask the students what
it means when you compare the two bars. Invite the students to tell
which hair color appears most frequently. Then ask them to find the
range and mode for this data set.
Project the Create a Graph Tool
and select the "Bar Graph" option from the drop-down menu found near the
bottom of the page. Ask a student to enter the data into the recording
section. Call on students to choose a name for the bar graph and the
colors of the bars. Choose the orientation [horizontal] of the graph to
match the graph that is on the board. Then select a student to hit the
"Generate graph" command.
In the example above, 4 students had blond hair, 6 had brown hair, 9 had brown hair, and 3 had red hair.
Ask the students to tell what they can learn from the chart
about the colors of hair represented in the room. Ask the students to
write two questions under the graph that can be answered by using the
data displayed on the graph. When they have done so, call on various
students to read their questions for the rest of the class to answer.
Next, ask the students to put their index cards upside down in a
pile where all can see them. Select one of the cards at random, and
call on students to tell which color they think it will be. Repeat
Next, ask whether they think there is any color of hair that could
not come up when a card is drawn. (Impossible hair colors will vary
according to the colors represented in your class.) Tell the students
that they are describing impossible events.
In order for students to experience certain probabilities, ask
whether there is any color of hair that is sure to come up when a card
is drawn. (Whether or not any hair colors are certain depends on the
hair colors represented in your class.) Tell the students that they are
describing events said to be certain.
To acquaint students with the likelihood that an event will occur,
ask the students whether there are any hair colors that occur
frequently in the class. Introduce the word "likely" by saying, "If I
draw a card without looking, is there any color that you think will be
more likely than others to come up?"
Ask the students to look at the graph to see whether the graph can
help them answer the question. [The hair colors represented by the
longer bars are more likely to come up.] Then ask what "certain" means
and whether any of the hair colors are certain to come up. Repeat with
"impossible." You may wish to begin these discussions with outrageous
impossible events (for example, there is a live elephant in class
today) and clearly certain events (for example, a given student is
breathing). Call on several volunteers to name a hair color and tell
whether it is likely, certain, or impossible to come up when an index
card is drawn.