Mathematics Grade 4
Objectives:
Students will be able to find the mode of a set of data using the
TI-73 graphing calculator.
Students will be able to find the median of a set of data using the
TI-73 graphing calculator.
Students will be able to find the mean of a set of data using the
TI-73 graphing calculator.
Students will manipulate data to discover how mean, mode, and median
change with changes in data.
Materials:
TI-73 Graphing Calculator
List of steps to use the TI-73 to determine mean, mode, and median
Teacher's model of the TI-73 with connector to overhead LED display
Overhead of picture of the TI-73
Calculator Riddles
Procedure:
Anticipatory Set
Students have been prepared for the using of the calculators by previous
lessons on all three terms; mean, mode, and median. Students have
learned the term median by reading its definition, then by solving median
problems. They have used Post-It notes to create a chart on the board
to discover the median number in a set of data.
Students constructed line plots on the board, again with Post-It notes,
and with paper and pencil to learn the concept of mode and students were
instructed in the steps to follow to determine the mean of a set of data.
Students were also given the calculators in advance to allow them to
explore the buttons and get comfortable with the key placement. An
overhead of the calculator was shown and each key pertinent to the succeeding
lessons was pointed out and explained.
Students were also given a series of riddles that required using a
calculator to find the answers. The riddles provided practice for
the student in the use of the calculator. This practice aided in
increasing the comfort level of students using the calculator and also
taught the students where certain keys were on the TI-73.
Check for Understanding
Ask each student in the room to give you a number and write it down
on a piece of paper at the same time to create a list of data. While
the class is writing the numbers down, the teacher should enter the data
into a list on the calculator. Then ask the students to find the
mode of the data. While they are deciding this, find the mode on
the calculator. The teacher should find the mode much faster than
the students. Students will believe that the teacher found mode first
because they are the teacher. So, repeat the demonstration, this
time, however, use a student to find the mode by directing them in the
steps to follow on the calculator. The student using the calculator
will still finish first.
Begin a discussion of the value of manipulating large sets of data,
for example, when determining populations and characteristics of the population.
The discussion should emphasize that when dealing with large sets of data,
using a paper and pencil is unreasonable.
Modeling and Guided Activity
Model with the LED overhead to display the steps needed to enter data
into the calculator. At every step, ask students if their screen
matches the overhead display to insure that all are following the correct
sequence. Determine the mean of the data and then use the same data
and find its median and mode.
Closure Activity
Ask the students how the medians value could change. If during
the discussion the idea that adding (or taking away) data to the set is
not mentioned, lead the students to it. Then demonstrate the change
by adding or taking away data. Ask the same question for mode and
mean and after taking suggestions from the class, demonstrate how adding,
deleting, or changing data affects these values.
Michigan Department of Education Content Strands and Benchmarks for Mathematics
Strand I CS 2 Patterns, Relationships and Functions
Students describe the relationships among variables, predict what will
happen to one variable as another is changed, analyze natural variation
and sources of variability, and compare patterns of change.
Benchmark 2
Recognize that change is often predictable, but variable, and that
patterns emerge that help to describe the change.
Benchmark 4
Use tables, charts, open sentences and hands-on models to represent
change and variability.
Strand III CS 1 Data Analysis and Statistics
Students collect and explore data, organize data into a useful form,
and develop skill in representing and reading data displayed in different
formats.
Benchmark 1
Collect and explore data through measuring, counting and conducting
surveys and experiments.
Benchmark 2
Organize data using concrete objects, pictures, tallies, tables, charts,
diagrams and graphs.
Benchmark 3
Present data using a variety of appropriate representations and explain
the meaning of the data.
Benchmark 4
Identify what data are needed to answer a particular question or solve
a problem, and design and implement strategies to obtain, organize and
present those data.
Strand III CS 2 Data Analysis and Statistics
Students examine data and describe characteristics of a distribution,
relate data to the situation from which they arose, and use data to answer
questions convincingly and persuasively.
Benchmark 2
Describe the shape of the data using informal language.