Materials: Sheet of unlined paper, set square, ruler

In this image, we see a figure being drawn about a vertical line of symmetry. Students analyze the relationship between the coordinates in corresponding points. What do you notice?

Vertical line of symmetry… only x values change

 Horizontal line of symmetry… only y values change

Note: Since A and F are points on the line, their distance from line of symmetry is zero, therefore they do not have a point symmetric about line m.

Here we see a graph of Fido’s weight from birth to age 28 months. Students are asked to comment about what they notice about Fido’s weight. What do you notice? (Get participants to respond.)

Students can answer a series of questions about this graph, like:

• 
  How much weight did Fido gain during the first 4 months?
  
• 
  Between 4 mos. and 8 mos.?
  
• 
  When did he gain weight most quickly? How do you know?
  
• 
  What happened to his weight between months 20-28? How do you know? What does the graph look like during these months?
  
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  What might the graph look like after 28 months?  really, no prediction can be made… many things could happen but we simply don’t know… this graph merely shows what DOES happen between birth and 28 months.
  

Here is an example of a problem that students must use to create a line graph about Magnolia School.

Students then answer a series of questions about this graph.

• 
  How many more fifth-grade students attended Magnolia in 2009 than in 2013?
  
• 
  Between which two years was there the greatest change in student population?
  
• 
  If the fifth-grade population continues to follow the same growth pattern as in 2012 and 2013, in what year will the number of students match 2008’s enrollment?