Teaching Algebra with Manipulatives

Using Overhead Manipulatives
(Use with Algebra 1, Lesson 5-7)
Scatter Plots
Objective Interpret points on a scatter plot.
Materials
• cloth tape measure
• lined paper transparency*
• centimeter grid transparency*
• transparency pens*
* available in Overhead Manipulative Resources
Demonstration
• On a lined paper transparency, prepare a
three-column chart with the headings Name,
Circumference, and Height.
• Attach a cloth measuring tape to a wall so that
it can be used for measuring height. Have a
student stand against the wall. Measure the
students height in inches and record it in the
chart on the lined transparency.
Sample answer: 68 in.
• Use another measuring tape to measure the
circumference of the student’s head in inches.
Record this measure. Sample answer: 22 in.
• Tell students, “You will organize this data using
the ordered pair (circumference, height).” Ask
them to name the ordered pair for this student.
Sample answer: (22, 68)
• On the centimeter grid transparency, prepare a
graph like the one above. Review plotting ordered
pairs and plot the sample ordered pair on the graph.
• Find the ordered pair for each student and plot
the data on the graph or have students complete
the scatter plot at their seats.
• Ask students whether there appears to be a
correlation between head circumference and height.
positive correlation You may want to review the
meaning of positive, negative and no correlation as
shown on pages 296–297 in the Student Edition.
Also, ask students if they see any other
relationships. Sample answer: Height is about
3 times the circumference.
Name Circumference Height
80
60
Height
40
20
0 8 16 24
Circumference
© Glencoe/McGraw-Hill 106 Teaching Algebra with Manipulatives